From ad4e59d301489137cfa3302174dc043deee8b2ee Mon Sep 17 00:00:00 2001
From: Adrian Braemer <bradrian@gmail.com>
Date: Thu, 9 Apr 2026 16:38:57 +0200
Subject: [PATCH] feat(models): add LineNumber newtype to replace raw usize for
 start_line/end_line

Introduce LineNumber (backed by NonZeroUsize) and LineSpan newtypes to
replace raw usize fields for start_line/end_line across all output,
detection, and internal types. This eliminates the possibility of
invalid zero-valued line numbers at the type level, removes runtime
guards that checked for start_line > 0, and makes the 1-indexed
semantics explicit in the type system.

Key changes:
- New src/models/line_number.rs with LineNumber(NonZeroUsize) and
  LineSpan { start, end } types
- All output structs (Match, Copyright, Holder, Author, OutputEmail,
  OutputURL) now use LineNumber for start_line/end_line
- All internal detection types (CopyrightDetection, HolderDetection,
  AuthorDetection, Token, EmailDetection, UrlDetection, LicenseMatch,
  FileRegion, DeclaredLicenseMatchMetadata) migrated
- SerializableLicenseMatch preserves JSON backward compatibility via
  serde(transparent) on LineNumber
- Removed now-unnecessary start_line > 0 / end_line > 0 guards
- line_for_pos() returns Option<LineNumber> instead of Option<usize>
- matched_text_from_text() takes (LineNumber, LineNumber) params
- ranges_overlap() takes LineNumber params (Ord-based comparison)
- LineSpan defined but not yet adopted (for future use)
---
 src/copyright/credits.rs                      |    9 +-
 src/copyright/detector.rs                     | 1303 +++++++++--------
 src/copyright/detector_author_heuristics.rs   |  124 +-
 src/copyright/detector_test.rs                |  128 +-
 src/copyright/lexer.rs                        |    9 +-
 src/copyright/lexer_test.rs                   |    7 +-
 src/copyright/line_tracking.rs                |   10 +-
 src/copyright/parser.rs                       |    5 +-
 src/copyright/parser_test.rs                  |    3 +-
 src/copyright/types.rs                        |   42 +-
 src/finder/emails.rs                          |    8 +-
 src/finder/golden_test.rs                     |    8 +-
 src/finder/mod.rs                             |    3 +-
 src/finder/urls.rs                            |    8 +-
 src/license_detection/aho_match.rs            |   12 +-
 src/license_detection/detection/analysis.rs   |   36 +-
 src/license_detection/detection/grouping.rs   |   15 +-
 src/license_detection/detection/identifier.rs |    5 +-
 src/license_detection/detection/mod.rs        |   80 +-
 src/license_detection/detection/types.rs      |   12 +-
 src/license_detection/hash_match.rs           |   11 +-
 .../match_refine/false_positive.rs            |    5 +-
 .../match_refine/filter_low_quality.rs        |   30 +-
 .../match_refine/handle_overlaps.rs           |   47 +-
 src/license_detection/match_refine/merge.rs   |   41 +-
 src/license_detection/match_refine/mod.rs     |   13 +-
 src/license_detection/models/license_match.rs |   13 +-
 src/license_detection/models/mod_tests.rs     |   63 +-
 src/license_detection/seq_match/matching.rs   |   11 +-
 src/license_detection/seq_match/mod.rs        |   20 +-
 src/license_detection/spdx_lid/mod.rs         |    7 +-
 src/license_detection/spdx_lid/test.rs        |    9 +-
 src/license_detection/tests.rs                |    3 +-
 src/license_detection/unknown_match.rs        |   35 +-
 src/main_test.rs                              |   25 +-
 src/models/file_info.rs                       |   33 +-
 src/models/line_number.rs                     |   72 +
 src/models/mod.rs                             |    2 +
 src/output/debian.rs                          |   10 +-
 src/output/html.rs                            |   24 +-
 src/output/mod.rs                             |   40 +-
 src/output/spdx.rs                            |    6 +-
 src/parsers/debian.rs                         |   28 +-
 src/parsers/license_normalization.rs          |   25 +-
 src/post_processing/classify_test.rs          |   16 +-
 src/post_processing/mod.rs                    |    5 +-
 src/post_processing/output_test.rs            |  232 +--
 src/post_processing/reference_following.rs    |   16 +-
 src/post_processing/summary/test.rs           |  195 +--
 src/post_processing/tallies_test.rs           |  124 +-
 src/scan_result_shaping/core_test.rs          |  148 +-
 src/scan_result_shaping/json_input_test.rs    |    9 +-
 src/scan_result_shaping/mod.rs                |   14 +-
 src/scanner/mod.rs                            |   10 +-
 src/scanner/process.rs                        |   39 +-
 tests/output_format_golden.rs                 |   20 +-
 tests/scanner_copyright_credits.rs            |    4 +-
 tests/scanner_integration.rs                  |   18 +-
 58 files changed, 1783 insertions(+), 1467 deletions(-)
 create mode 100644 src/models/line_number.rs

diff --git a/src/copyright/credits.rs b/src/copyright/credits.rs
index fab9b7242..8ab486a87 100644
--- a/src/copyright/credits.rs
+++ b/src/copyright/credits.rs
@@ -11,6 +11,7 @@
 use std::path::Path;
 
 use super::types::AuthorDetection;
+use crate::models::LineNumber;
 
 /// Filenames recognized as CREDITS/AUTHORS files (case-insensitive)
 const CREDITS_FILENAMES: &[&str] = &[
@@ -118,8 +119,8 @@ fn process_credit_group(group: &[(usize, &str)]) -> Option<AuthorDetection> {
 
     Some(AuthorDetection {
         author,
-        start_line,
-        end_line,
+        start_line: LineNumber::new(start_line).expect("invalid line number"),
+        end_line: LineNumber::new(end_line).expect("invalid line number"),
     })
 }
 
@@ -154,8 +155,8 @@ W: http://www.randombit.net/
             authors[0].author,
             "Jack Lloyd lloyd@randombit.net http://www.randombit.net/"
         );
-        assert_eq!(authors[0].start_line, 1);
-        assert_eq!(authors[0].end_line, 3);
+        assert_eq!(authors[0].start_line, LineNumber::ONE);
+        assert_eq!(authors[0].end_line, LineNumber::new(3).unwrap());
     }
 
     #[test]
diff --git a/src/copyright/detector.rs b/src/copyright/detector.rs
index dc3c40e8c..0b7c4e863 100644
--- a/src/copyright/detector.rs
+++ b/src/copyright/detector.rs
@@ -32,6 +32,7 @@ use super::refiner::{
 use super::types::{
     AuthorDetection, CopyrightDetection, HolderDetection, ParseNode, PosTag, Token, TreeLabel,
 };
+use crate::models::LineNumber;
 
 const NON_COPYRIGHT_LABELS: &[TreeLabel] = &[];
 const NON_HOLDER_LABELS: &[TreeLabel] = &[TreeLabel::YrRange, TreeLabel::YrAnd];
@@ -166,7 +167,7 @@ pub fn detect_copyrights_from_text_with_deadline(
             if let Some(det) = extract_original_author_additional_contributors(&tree)
                 && !authors
                     .iter()
-                    .any(|a| a.author == det.author && a.start_line == det.start_line)
+                    .any(|a| a.author == det.author && a.start_line.get() == det.start_line.get())
             {
                 authors.push(det);
             }
@@ -188,12 +189,12 @@ pub fn detect_copyrights_from_text_with_deadline(
                 let mut ok = true;
                 for t in tree.iter().flat_map(collect_all_leaves) {
                     if let Some(existing) = line {
-                        if existing != t.start_line {
+                        if existing != t.start_line.get() {
                             ok = false;
                             break;
                         }
                     } else {
-                        line = Some(t.start_line);
+                        line = Some(t.start_line.get());
                     }
                 }
                 ok
@@ -239,7 +240,7 @@ pub fn detect_copyrights_from_text_with_deadline(
             if let Some(det) = extract_original_author_additional_contributors(&tree)
                 && !authors
                     .iter()
-                    .any(|a| a.author == det.author && a.start_line == det.start_line)
+                    .any(|a| a.author == det.author && a.start_line.get() == det.start_line.get())
             {
                 authors.push(det);
             }
@@ -324,10 +325,6 @@ pub fn detect_copyrights_from_text_with_deadline(
     dedupe_exact_span_holders(&mut holders);
     dedupe_exact_span_authors(&mut authors);
 
-    copyrights.retain(|c| c.start_line > 0 && c.end_line > 0);
-    holders.retain(|h| h.start_line > 0 && h.end_line > 0);
-    authors.retain(|a| a.start_line > 0 && a.end_line > 0);
-
     (copyrights, holders, authors)
 }
 
@@ -387,10 +384,11 @@ fn add_missing_holders_for_bare_c_name_year_suffixes(
         if holder.is_empty() {
             continue;
         }
-        if holders
-            .iter()
-            .any(|h| h.start_line == c.start_line && h.end_line == c.end_line && h.holder == holder)
-        {
+        if holders.iter().any(|h| {
+            h.start_line.get() == c.start_line.get()
+                && h.end_line.get() == c.end_line.get()
+                && h.holder == holder
+        }) {
             continue;
         }
         holders.push(HolderDetection {
@@ -525,7 +523,7 @@ fn drop_shadowed_year_only_copyright_prefixes_same_start_line(
         std::collections::HashMap::new();
     for c in copyrights.iter() {
         by_start
-            .entry(c.start_line)
+            .entry(c.start_line.get())
             .or_default()
             .push(normalize_whitespace(&c.copyright));
     }
@@ -535,7 +533,7 @@ fn drop_shadowed_year_only_copyright_prefixes_same_start_line(
         if !YEAR_ONLY_RE.is_match(short.as_str()) {
             return true;
         }
-        let Some(all) = by_start.get(&c.start_line) else {
+        let Some(all) = by_start.get(&c.start_line.get()) else {
             return true;
         };
         !all.iter()
@@ -559,7 +557,7 @@ fn drop_year_only_copyrights_shadowed_by_previous_software_copyright_line(
     });
 
     copyrights.retain(|c| {
-        if c.start_line <= 1 {
+        if c.start_line <= LineNumber::ONE {
             return true;
         }
         let Some(cap) = YEAR_ONLY_RE.captures(c.copyright.trim()) else {
@@ -570,12 +568,12 @@ fn drop_year_only_copyrights_shadowed_by_previous_software_copyright_line(
             return true;
         }
 
-        let this_raw = raw_lines.get(c.start_line - 1).copied().unwrap_or("");
+        let this_raw = raw_lines.get(c.start_line.get() - 1).copied().unwrap_or("");
         if this_raw.to_ascii_lowercase().contains("software copyright") {
             return false;
         }
 
-        let prev_prepared = prepared_cache.get(c.start_line - 1).unwrap_or("");
+        let prev_prepared = prepared_cache.get(c.start_line.get() - 1).unwrap_or("");
         if let Some(prev) = PREV_SOFTWARE_RE.captures(prev_prepared) {
             let y2 = prev.name("year").map(|m| m.as_str()).unwrap_or("");
             return y2 != year;
@@ -658,12 +656,12 @@ fn merge_multiline_person_year_copyright_continuations(
 
         if !copyrights
             .iter()
-            .any(|c| c.start_line == ln1 && c.end_line == ln2 && c.copyright == refined)
+            .any(|c| c.start_line.get() == ln1 && c.end_line.get() == ln2 && c.copyright == refined)
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined.clone(),
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
 
@@ -671,12 +669,12 @@ fn merge_multiline_person_year_copyright_continuations(
         if let Some(h) = refine_holder_in_copyright_context(&raw_holder)
             && !holders
                 .iter()
-                .any(|x| x.start_line == ln1 && x.end_line == ln2 && x.holder == h)
+                .any(|x| x.start_line.get() == ln1 && x.end_line.get() == ln2 && x.holder == h)
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
     }
@@ -692,7 +690,7 @@ fn add_embedded_copyright_clause_variants(copyrights: &mut Vec<CopyrightDetectio
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     let mut to_add = Vec::new();
@@ -717,7 +715,7 @@ fn add_embedded_copyright_clause_variants(copyrights: &mut Vec<CopyrightDetectio
         {
             continue;
         }
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if !existing.contains(&key) {
             to_add.push(CopyrightDetection {
                 copyright: refined,
@@ -742,11 +740,11 @@ fn add_found_at_short_variants(
 
     let existing_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let existing_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     let mut new_c = Vec::new();
@@ -760,7 +758,7 @@ fn add_found_at_short_variants(
             continue;
         }
         let short = format!("(c) by {name}");
-        let key = (c.start_line, c.end_line, short.clone());
+        let key = (c.start_line.get(), c.end_line.get(), short.clone());
         if !existing_c.contains(&key) {
             new_c.push(CopyrightDetection {
                 copyright: short,
@@ -770,7 +768,7 @@ fn add_found_at_short_variants(
         }
 
         let holder_short = name.to_string();
-        let hkey = (c.start_line, c.end_line, holder_short.clone());
+        let hkey = (c.start_line.get(), c.end_line.get(), holder_short.clone());
         if !existing_h.contains(&hkey) {
             new_h.push(HolderDetection {
                 holder: holder_short,
@@ -829,7 +827,7 @@ fn drop_shadowed_linux_foundation_holder_copyrights_same_line(
         if let Some(cap) = WITH_C_RE.captures(c.copyright.trim()) {
             let years = cap.name("years").map(|m| m.as_str()).unwrap_or("").trim();
             if !years.is_empty() {
-                years_by_line.insert((c.start_line, years.to_string()));
+                years_by_line.insert((c.start_line.get(), years.to_string()));
             }
         }
     }
@@ -842,7 +840,7 @@ fn drop_shadowed_linux_foundation_holder_copyrights_same_line(
         if years.is_empty() {
             return true;
         }
-        !years_by_line.contains(&(c.start_line, years.to_string()))
+        !years_by_line.contains(&(c.start_line.get(), years.to_string()))
     });
 }
 
@@ -875,19 +873,21 @@ fn restore_linux_foundation_copyrights_from_raw_lines(
         let full = normalize_whitespace(&format!("Copyright (c) {years} Linux Foundation"));
         if copyrights
             .iter()
-            .any(|c| c.start_line == ln && c.end_line == ln && c.copyright == full)
+            .any(|c| c.start_line.get() == ln && c.end_line.get() == ln && c.copyright == full)
         {
             continue;
         }
 
         to_add.push(CopyrightDetection {
             copyright: full.clone(),
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
 
         let bare = normalize_whitespace(&format!("Copyright (c) {years}"));
-        copyrights.retain(|c| !(c.start_line == ln && c.end_line == ln && c.copyright == bare));
+        copyrights.retain(|c| {
+            !(c.start_line.get() == ln && c.end_line.get() == ln && c.copyright == bare)
+        });
     }
 
     copyrights.extend(to_add);
@@ -906,15 +906,15 @@ fn add_bare_email_variants_for_escaped_angle_lines(
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     let mut to_add = Vec::new();
     for c in copyrights.iter() {
-        if c.start_line == 0 || c.end_line == 0 || c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             continue;
         }
-        let Some(raw) = raw_lines.get(c.start_line - 1) else {
+        let Some(raw) = raw_lines.get(c.start_line.get() - 1) else {
             continue;
         };
         let raw_lower = raw.to_ascii_lowercase();
@@ -930,7 +930,7 @@ fn add_bare_email_variants_for_escaped_angle_lines(
         let Some(refined) = refine_copyright(&bare) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if !existing.contains(&key) {
             to_add.push(CopyrightDetection {
                 copyright: refined,
@@ -952,13 +952,13 @@ fn drop_comma_holders_shadowed_by_space_version_same_span(holders: &mut Vec<Hold
     let mut by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .insert(h.holder.clone());
     }
 
     holders.retain(|h| {
-        let Some(set) = by_span.get(&(h.start_line, h.end_line)) else {
+        let Some(set) = by_span.get(&(h.start_line.get(), h.end_line.get())) else {
             return true;
         };
         if !h.holder.contains(',') {
@@ -1019,8 +1019,8 @@ fn normalize_company_suffix_period_holder_variants(holders: &mut Vec<HolderDetec
             Some(Occurrence {
                 key,
                 holder: h.holder.clone(),
-                start_line: h.start_line,
-                end_line: h.end_line,
+                start_line: h.start_line.get(),
+                end_line: h.end_line.get(),
                 dotted: has_trailing_period(&h.holder),
             })
         })
@@ -1065,7 +1065,7 @@ fn normalize_company_suffix_period_holder_variants(holders: &mut Vec<HolderDetec
         let Some(spans) = affected_spans_by_key.get(&key) else {
             continue;
         };
-        if spans.contains(&(h.start_line, h.end_line)) {
+        if spans.contains(&(h.start_line.get(), h.end_line.get())) {
             h.holder = canonical.clone();
         }
     }
@@ -1087,11 +1087,11 @@ fn add_confidential_short_variants_late(
 
     let mut existing_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut existing_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for c in copyrights.clone() {
@@ -1106,7 +1106,7 @@ fn add_confidential_short_variants_late(
         let Some(short_c) = refine_copyright(&short_c_raw) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, short_c.clone());
+        let key = (c.start_line.get(), c.end_line.get(), short_c.clone());
         if existing_c.insert(key) {
             copyrights.push(CopyrightDetection {
                 copyright: short_c,
@@ -1116,7 +1116,7 @@ fn add_confidential_short_variants_late(
         }
 
         let short_h = "Confidential".to_string();
-        let hkey = (c.start_line, c.end_line, short_h.clone());
+        let hkey = (c.start_line.get(), c.end_line.get(), short_h.clone());
         if existing_h.insert(hkey) {
             holders.push(HolderDetection {
                 holder: short_h,
@@ -1149,7 +1149,7 @@ fn split_multiline_holder_lists_from_copyright_email_sequences(
     let mut to_remove: HashSet<(usize, usize, String)> = HashSet::new();
 
     for c in copyrights {
-        if c.end_line <= c.start_line {
+        if c.end_line.get() <= c.start_line.get() {
             continue;
         }
 
@@ -1188,12 +1188,12 @@ fn split_multiline_holder_lists_from_copyright_email_sequences(
 
         let mut has_joined_holder = false;
         for h in holders.iter() {
-            if h.start_line == c.start_line
-                && h.end_line == c.end_line
+            if h.start_line.get() == c.start_line.get()
+                && h.end_line.get() == c.end_line.get()
                 && normalize_whitespace(&h.holder) == joined
             {
                 has_joined_holder = true;
-                to_remove.insert((h.start_line, h.end_line, h.holder.clone()));
+                to_remove.insert((h.start_line.get(), h.end_line.get(), h.holder.clone()));
             }
         }
 
@@ -1202,10 +1202,10 @@ fn split_multiline_holder_lists_from_copyright_email_sequences(
         }
 
         for name in split_names {
-            let key = (c.start_line, c.end_line, name.clone());
+            let key = (c.start_line.get(), c.end_line.get(), name.clone());
             if !holders
                 .iter()
-                .any(|h| (h.start_line, h.end_line, h.holder.clone()) == key)
+                .any(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()) == key)
             {
                 to_add.push(HolderDetection {
                     holder: name,
@@ -1217,7 +1217,9 @@ fn split_multiline_holder_lists_from_copyright_email_sequences(
     }
 
     if !to_remove.is_empty() {
-        holders.retain(|h| !to_remove.contains(&(h.start_line, h.end_line, h.holder.clone())));
+        holders.retain(|h| {
+            !to_remove.contains(&(h.start_line.get(), h.end_line.get(), h.holder.clone()))
+        });
     }
     if !to_add.is_empty() {
         holders.extend(to_add);
@@ -1241,11 +1243,11 @@ fn add_karlsruhe_university_short_variants(
 
     let mut existing_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut existing_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for c in copyrights.clone() {
@@ -1262,7 +1264,7 @@ fn add_karlsruhe_university_short_variants(
         if short == c.copyright {
             continue;
         }
-        let key = (c.start_line, c.end_line, short.clone());
+        let key = (c.start_line.get(), c.end_line.get(), short.clone());
         if existing_c.insert(key) {
             copyrights.push(CopyrightDetection {
                 copyright: short,
@@ -1286,7 +1288,7 @@ fn add_karlsruhe_university_short_variants(
         if short == h.holder {
             continue;
         }
-        let key = (h.start_line, h.end_line, short.clone());
+        let key = (h.start_line.get(), h.end_line.get(), short.clone());
         if existing_h.insert(key) {
             holders.push(HolderDetection {
                 holder: short,
@@ -1321,7 +1323,7 @@ fn add_intel_and_sun_non_portions_variants(
 
     let mut existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     for c in copyrights.clone() {
@@ -1333,7 +1335,7 @@ fn add_intel_and_sun_non_portions_variants(
                 let candidate =
                     normalize_whitespace(&format!("Copyright {year} Sun Microsystems{tail}"));
                 if let Some(refined) = refine_copyright(&candidate) {
-                    let key = (c.start_line, c.end_line, refined.clone());
+                    let key = (c.start_line.get(), c.end_line.get(), refined.clone());
                     if existing.insert(key) {
                         copyrights.push(CopyrightDetection {
                             copyright: refined,
@@ -1346,10 +1348,10 @@ fn add_intel_and_sun_non_portions_variants(
         }
 
         if PORTIONS_INTEL_RE.is_match(trimmed)
-            && (c.end_line > c.start_line || trimmed.contains('('))
+            && (c.end_line.get() > c.start_line.get() || trimmed.contains('('))
         {
             let mut joined = String::new();
-            for ln in c.start_line..=c.end_line {
+            for ln in c.start_line.get()..=c.end_line.get() {
                 if let Some(p) = prepared_cache.get(ln) {
                     if !joined.is_empty() {
                         joined.push(' ');
@@ -1364,7 +1366,7 @@ fn add_intel_and_sun_non_portions_variants(
                     let candidate =
                         normalize_whitespace(&format!("Copyright 2002 Intel ({emails})"));
                     if let Some(refined) = refine_copyright(&candidate) {
-                        let key = (c.start_line, c.end_line, refined.clone());
+                        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
                         if existing.insert(key) {
                             copyrights.push(CopyrightDetection {
                                 copyright: refined,
@@ -1390,7 +1392,7 @@ fn add_first_angle_email_only_variants(copyrights: &mut Vec<CopyrightDetection>)
 
     let mut existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     for c in copyrights.clone() {
@@ -1405,7 +1407,7 @@ fn add_first_angle_email_only_variants(copyrights: &mut Vec<CopyrightDetection>)
         let Some(refined) = refine_copyright(prefix) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if existing.insert(key) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
@@ -1431,13 +1433,13 @@ fn drop_shadowed_angle_email_prefix_copyrights_same_span(copyrights: &mut Vec<Co
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for c in copyrights.iter() {
         by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .push(c.copyright.clone());
     }
 
     copyrights.retain(|c| {
-        let span = (c.start_line, c.end_line);
+        let span = (c.start_line.get(), c.end_line.get());
         let Some(all) = by_span.get(&span) else {
             return true;
         };
@@ -1485,7 +1487,7 @@ fn drop_shadowed_quote_before_email_variants_same_span(copyrights: &mut Vec<Copy
     let mut exact_by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for c in copyrights.iter() {
         exact_by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .insert(c.copyright.clone());
     }
@@ -1494,7 +1496,7 @@ fn drop_shadowed_quote_before_email_variants_same_span(copyrights: &mut Vec<Copy
         if !c.copyright.contains('\'') || !c.copyright.contains('@') {
             return true;
         }
-        let span = (c.start_line, c.end_line);
+        let span = (c.start_line.get(), c.end_line.get());
         let Some(exact) = exact_by_span.get(&span) else {
             return true;
         };
@@ -1547,7 +1549,7 @@ fn add_but_suffix_short_variants(copyrights: &mut Vec<CopyrightDetection>) {
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     let mut to_add = Vec::new();
@@ -1563,7 +1565,7 @@ fn add_but_suffix_short_variants(copyrights: &mut Vec<CopyrightDetection>) {
         let Some(refined) = refine_copyright(prefix) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if !existing.contains(&key) {
             to_add.push(CopyrightDetection {
                 copyright: refined,
@@ -1586,11 +1588,11 @@ fn add_at_affiliation_short_variants(
 
     let existing_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let existing_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     let mut to_add_c = Vec::new();
@@ -1605,7 +1607,7 @@ fn add_at_affiliation_short_variants(
         let Some(refined) = refine_copyright(head) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if !existing_c.contains(&key) {
             to_add_c.push(CopyrightDetection {
                 copyright: refined,
@@ -1631,7 +1633,7 @@ fn add_at_affiliation_short_variants(
         let Some(refined) = refine_holder_in_copyright_context(head) else {
             continue;
         };
-        let key = (h.start_line, h.end_line, refined.clone());
+        let key = (h.start_line.get(), h.end_line.get(), refined.clone());
         if !existing_h.contains(&key) {
             to_add_h.push(HolderDetection {
                 holder: refined,
@@ -1654,22 +1656,22 @@ fn add_missing_copyrights_for_holder_lines_with_emails(
 
     let mut copyright_lines: HashSet<usize> = HashSet::new();
     for c in copyrights.iter() {
-        if c.start_line == c.end_line {
-            copyright_lines.insert(c.start_line);
+        if c.start_line.get() == c.end_line.get() {
+            copyright_lines.insert(c.start_line.get());
         }
     }
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     let mut to_add = Vec::new();
     for h in holders.iter() {
-        if h.start_line != h.end_line {
+        if h.start_line.get() != h.end_line.get() {
             continue;
         }
-        let ln = h.start_line;
+        let ln = h.start_line.get();
         if ln == 0 || ln > prepared_cache.len() {
             continue;
         }
@@ -1702,8 +1704,8 @@ fn add_missing_copyrights_for_holder_lines_with_emails(
         }
         to_add.push(CopyrightDetection {
             copyright: refined,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).expect("invalid line number"),
+            end_line: LineNumber::new(ln).expect("invalid line number"),
         });
     }
     copyrights.extend(to_add);
@@ -1727,7 +1729,7 @@ fn extend_inline_obfuscated_angle_email_suffixes(
     });
 
     for c in copyrights.iter_mut() {
-        if c.start_line == 0 || c.end_line == 0 || c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             continue;
         }
         if c.copyright.to_ascii_lowercase().contains(" at ")
@@ -1736,7 +1738,7 @@ fn extend_inline_obfuscated_angle_email_suffixes(
             continue;
         }
 
-        let ln = c.start_line;
+        let ln = c.start_line.get();
         let Some(refined_line) = refined_line_cache
             .entry(ln)
             .or_insert_with(|| {
@@ -1831,7 +1833,7 @@ fn strip_lone_obfuscated_angle_email_user_tokens(
 
         for c in copyrights
             .iter_mut()
-            .filter(|c| c.start_line == ln && c.end_line == ln)
+            .filter(|c| c.start_line.get() == ln && c.end_line.get() == ln)
         {
             let lower = c.copyright.to_ascii_lowercase();
             if lower.contains(" at ") || lower.contains(" dot ") {
@@ -1849,7 +1851,7 @@ fn strip_lone_obfuscated_angle_email_user_tokens(
 
         for h in holders
             .iter_mut()
-            .filter(|h| h.start_line == ln && h.end_line == ln)
+            .filter(|h| h.start_line.get() == ln && h.end_line.get() == ln)
         {
             let lower = h.holder.to_ascii_lowercase();
             if lower.contains(" at ") || lower.contains(" dot ") {
@@ -1884,7 +1886,7 @@ fn add_at_domain_variants_for_short_net_angle_emails(
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     let mut to_add = Vec::new();
@@ -1903,7 +1905,7 @@ fn add_at_domain_variants_for_short_net_angle_emails(
         let Some(refined) = refine_copyright(&replaced) else {
             continue;
         };
-        let key = (c.start_line, c.end_line, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get(), refined.clone());
         if existing.contains(&key) {
             continue;
         }
@@ -1929,7 +1931,7 @@ fn drop_shadowed_plain_email_prefix_copyrights_same_span(copyrights: &mut Vec<Co
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for c in copyrights.iter() {
         by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .push(c.copyright.clone());
     }
@@ -1960,7 +1962,9 @@ fn drop_shadowed_plain_email_prefix_copyrights_same_span(copyrights: &mut Vec<Co
         }
     }
 
-    copyrights.retain(|c| !to_drop.contains(&(c.start_line, c.end_line, c.copyright.clone())));
+    copyrights.retain(|c| {
+        !to_drop.contains(&(c.start_line.get(), c.end_line.get(), c.copyright.clone()))
+    });
 }
 
 fn drop_single_line_copyrights_shadowed_by_multiline_same_start(
@@ -1979,7 +1983,7 @@ fn drop_single_line_copyrights_shadowed_by_multiline_same_start(
 
     let mut multi_keys: HashSet<(usize, String, String)> = HashSet::new();
     for c in copyrights.iter() {
-        if c.end_line <= c.start_line {
+        if c.end_line.get() <= c.start_line.get() {
             continue;
         }
         let Some(cap) = YEARS_EMAIL_RE.captures(c.copyright.trim()) else {
@@ -1994,7 +1998,7 @@ fn drop_single_line_copyrights_shadowed_by_multiline_same_start(
         if years_norm.is_empty() || email.is_empty() {
             continue;
         }
-        multi_keys.insert((c.start_line, years_norm, email.to_ascii_lowercase()));
+        multi_keys.insert((c.start_line.get(), years_norm, email.to_ascii_lowercase()));
     }
 
     if multi_keys.is_empty() {
@@ -2002,10 +2006,7 @@ fn drop_single_line_copyrights_shadowed_by_multiline_same_start(
     }
 
     copyrights.retain(|c| {
-        if c.start_line == 0 {
-            return true;
-        }
-        if c.end_line != c.start_line {
+        if c.end_line.get() != c.start_line.get() {
             return true;
         }
         let Some(cap) = YEARS_EMAIL_RE.captures(c.copyright.trim()) else {
@@ -2020,7 +2021,7 @@ fn drop_single_line_copyrights_shadowed_by_multiline_same_start(
         if years_norm.is_empty() || email.is_empty() {
             return true;
         }
-        !multi_keys.contains(&(c.start_line, years_norm, email.to_ascii_lowercase()))
+        !multi_keys.contains(&(c.start_line.get(), years_norm, email.to_ascii_lowercase()))
     });
 }
 
@@ -2038,11 +2039,11 @@ fn normalize_french_support_disclaimer_copyrights(
 
     let existing_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let existing_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     let mut to_add_c = Vec::new();
@@ -2060,7 +2061,7 @@ fn normalize_french_support_disclaimer_copyrights(
         let Some(short) = refine_copyright(short_raw) else {
             continue;
         };
-        let ckey = (c.start_line, c.end_line, short.clone());
+        let ckey = (c.start_line.get(), c.end_line.get(), short.clone());
         if !existing_c.contains(&ckey) {
             to_add_c.push(CopyrightDetection {
                 copyright: short,
@@ -2071,7 +2072,7 @@ fn normalize_french_support_disclaimer_copyrights(
         let Some(refined_email) = refine_holder_in_copyright_context(email) else {
             continue;
         };
-        let hkey = (c.start_line, c.end_line, refined_email.clone());
+        let hkey = (c.start_line.get(), c.end_line.get(), refined_email.clone());
         if !existing_h.contains(&hkey) {
             to_add_h.push(HolderDetection {
                 holder: refined_email,
@@ -2111,13 +2112,13 @@ fn drop_shadowed_email_org_location_suffixes_same_span(
     let mut exact_c_by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for c in copyrights.iter() {
         exact_c_by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .insert(c.copyright.clone());
     }
 
     copyrights.retain(|c| {
-        let span = (c.start_line, c.end_line);
+        let span = (c.start_line.get(), c.end_line.get());
         let Some(set) = exact_c_by_span.get(&span) else {
             return true;
         };
@@ -2138,7 +2139,7 @@ fn drop_shadowed_email_org_location_suffixes_same_span(
     let mut exact_h_by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for h in holders.iter() {
         exact_h_by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .insert(h.holder.clone());
     }
@@ -2155,9 +2156,9 @@ fn drop_shadowed_email_org_location_suffixes_same_span(
         let Some(refined_email) = refine_holder_in_copyright_context(email) else {
             continue;
         };
-        let key = (h.start_line, h.end_line, refined_email.clone());
+        let key = (h.start_line.get(), h.end_line.get(), refined_email.clone());
         if exact_h_by_span
-            .get(&(h.start_line, h.end_line))
+            .get(&(h.start_line.get(), h.end_line.get()))
             .is_some_and(|set| set.contains(&refined_email))
         {
             continue;
@@ -2168,14 +2169,14 @@ fn drop_shadowed_email_org_location_suffixes_same_span(
             end_line: h.end_line,
         });
         exact_h_by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .insert(key.2);
     }
     holders.extend(to_add_h);
 
     holders.retain(|h| {
-        let span = (h.start_line, h.end_line);
+        let span = (h.start_line.get(), h.end_line.get());
         let Some(set) = exact_h_by_span.get(&span) else {
             return true;
         };
@@ -2207,7 +2208,7 @@ fn add_pipe_read_parenthetical_variants(
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     for i in 0..prepared_cache.len().saturating_sub(1) {
@@ -2236,8 +2237,8 @@ fn add_pipe_read_parenthetical_variants(
         if !existing.contains(&key) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
     }
@@ -2256,7 +2257,7 @@ fn add_from_url_parenthetical_copyright_variants(
 
     let existing: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     for i in 0..prepared_cache.len() {
@@ -2282,8 +2283,8 @@ fn add_from_url_parenthetical_copyright_variants(
         if !existing.contains(&key) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -2303,13 +2304,13 @@ fn drop_shadowed_acronym_location_suffix_copyrights_same_span(
     let mut by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for c in copyrights.iter() {
         by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .insert(c.copyright.clone());
     }
 
     copyrights.retain(|c| {
-        let span = (c.start_line, c.end_line);
+        let span = (c.start_line.get(), c.end_line.get());
         let Some(set) = by_span.get(&span) else {
             return true;
         };
@@ -2356,10 +2357,12 @@ fn drop_json_description_metadata_copyrights_and_holders(
 
     let mut retained_spans: HashSet<(usize, usize)> = HashSet::new();
     copyrights.retain(|copyright| {
-        let Some(window) =
-            json_window_for_span(raw_lines, copyright.start_line, copyright.end_line)
-        else {
-            retained_spans.insert((copyright.start_line, copyright.end_line));
+        let Some(window) = json_window_for_span(
+            raw_lines,
+            copyright.start_line.get(),
+            copyright.end_line.get(),
+        ) else {
+            retained_spans.insert((copyright.start_line.get(), copyright.end_line.get()));
             return true;
         };
 
@@ -2371,16 +2374,17 @@ fn drop_json_description_metadata_copyrights_and_holders(
             || lower.contains("\"url\"");
         let keep = !description_like || JSON_COPYRIGHT_KEY_RE.is_match(&window);
         if keep {
-            retained_spans.insert((copyright.start_line, copyright.end_line));
+            retained_spans.insert((copyright.start_line.get(), copyright.end_line.get()));
         }
         keep
     });
 
     holders.retain(|holder| {
-        if retained_spans.contains(&(holder.start_line, holder.end_line)) {
+        if retained_spans.contains(&(holder.start_line.get(), holder.end_line.get())) {
             return true;
         }
-        let Some(window) = json_window_for_span(raw_lines, holder.start_line, holder.end_line)
+        let Some(window) =
+            json_window_for_span(raw_lines, holder.start_line.get(), holder.end_line.get())
         else {
             return true;
         };
@@ -2441,7 +2445,7 @@ fn restore_url_slash_before_closing_paren_from_raw_lines(
     }
 
     for c in copyrights.iter_mut() {
-        for ln in c.start_line..=c.end_line {
+        for ln in c.start_line.get()..=c.end_line.get() {
             let Some(pairs) = replacements.get(&ln) else {
                 continue;
             };
@@ -2555,30 +2559,30 @@ fn extract_mso_document_properties_copyrights(
         let ckey = (desc_line, end_line, copy_refined.clone());
         if !copyrights
             .iter()
-            .any(|c| (c.start_line, c.end_line, c.copyright.clone()) == ckey)
+            .any(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()) == ckey)
         {
             copyrights.push(CopyrightDetection {
                 copyright: copy_refined,
-                start_line: desc_line,
-                end_line,
+                start_line: LineNumber::new(desc_line).expect("valid"),
+                end_line: LineNumber::new(end_line).expect("valid"),
             });
         }
         let hkey = (desc_line, end_line, holder_refined.clone());
         if !holders
             .iter()
-            .any(|h| (h.start_line, h.end_line, h.holder.clone()) == hkey)
+            .any(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()) == hkey)
         {
             holders.push(HolderDetection {
                 holder: holder_refined,
-                start_line: desc_line,
-                end_line,
+                start_line: LineNumber::new(desc_line).expect("valid"),
+                end_line: LineNumber::new(end_line).expect("valid"),
             });
         }
     }
 
     let plain = format!("Copyright {year}");
     copyrights.retain(|c| {
-        !(c.start_line == desc_line && c.end_line == desc_line && c.copyright == plain)
+        !(c.start_line.get() == desc_line && c.end_line.get() == desc_line && c.copyright == plain)
     });
 
     let shadow_non_confidential = normalize_whitespace(&format!("{last_author} Copyright {year}"));
@@ -2591,24 +2595,25 @@ fn extract_mso_document_properties_copyrights(
         let short_c = format!("Copyright {year} Confidential");
         let short_h = "Confidential".to_string();
         if let Some(rc) = refine_copyright(&short_c)
-            && !copyrights
-                .iter()
-                .any(|c| c.start_line == desc_line && c.end_line == desc_line && c.copyright == rc)
+            && !copyrights.iter().any(|c| {
+                c.start_line.get() == desc_line
+                    && c.end_line.get() == desc_line
+                    && c.copyright == rc
+            })
         {
             copyrights.push(CopyrightDetection {
                 copyright: rc,
-                start_line: desc_line,
-                end_line: desc_line,
+                start_line: LineNumber::new(desc_line).expect("valid"),
+                end_line: LineNumber::new(desc_line).expect("valid"),
             });
         }
-        if !holders
-            .iter()
-            .any(|h| h.start_line == desc_line && h.end_line == desc_line && h.holder == short_h)
-        {
+        if !holders.iter().any(|h| {
+            h.start_line.get() == desc_line && h.end_line.get() == desc_line && h.holder == short_h
+        }) {
             holders.push(HolderDetection {
                 holder: short_h,
-                start_line: desc_line,
-                end_line: desc_line,
+                start_line: LineNumber::new(desc_line).expect("valid"),
+                end_line: LineNumber::new(desc_line).expect("valid"),
             });
         }
     }
@@ -2665,14 +2670,14 @@ fn expand_year_only_copyrights_with_by_name_prefix(
 
     let mut seen_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for c in copyrights.iter_mut() {
         if !YEAR_ONLY_COPY_RE.is_match(c.copyright.trim()) {
             continue;
         }
-        let Some(line) = prepared_cache.get(c.start_line) else {
+        let Some(line) = prepared_cache.get(c.start_line.get()) else {
             continue;
         };
         let Some(cap) = BY_NAME_RE.captures(line) else {
@@ -2699,7 +2704,7 @@ fn expand_year_only_copyrights_with_by_name_prefix(
         c.copyright = format!("{name}, Copyright (c) {year}");
 
         if let Some(h) = refine_holder_in_copyright_context(name) {
-            let key = (c.start_line, c.end_line, h.clone());
+            let key = (c.start_line.get(), c.end_line.get(), h.clone());
             if seen_h.insert(key) {
                 holders.push(HolderDetection {
                     holder: h,
@@ -2725,11 +2730,11 @@ fn expand_year_only_copyrights_with_read_the_suffix(
 
     let mut seen_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     let current = copyrights.clone();
@@ -2737,13 +2742,13 @@ fn expand_year_only_copyrights_with_read_the_suffix(
     let mut new_holders = Vec::new();
 
     for c in current.iter() {
-        if c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             continue;
         }
         if !YEAR_ONLY_RE.is_match(c.copyright.trim()) {
             continue;
         }
-        let Some(next_line) = prepared_cache.get(c.end_line + 1) else {
+        let Some(next_line) = prepared_cache.get(c.end_line.get() + 1) else {
             continue;
         };
         let next_trim = next_line.trim();
@@ -2755,7 +2760,7 @@ fn expand_year_only_copyrights_with_read_the_suffix(
         let Some(refined) = refine_copyright(&raw) else {
             continue;
         };
-        let key = (c.start_line, c.end_line + 1, refined.clone());
+        let key = (c.start_line.get(), c.end_line.get() + 1, refined.clone());
         if seen_c.insert(key) {
             new_copyrights.push(CopyrightDetection {
                 copyright: refined,
@@ -2764,7 +2769,7 @@ fn expand_year_only_copyrights_with_read_the_suffix(
             });
         }
         if let Some(h) = refine_holder_in_copyright_context(tail) {
-            let hkey = (c.end_line + 1, c.end_line + 1, h.clone());
+            let hkey = (c.end_line.get() + 1, c.end_line.get() + 1, h.clone());
             if seen_h.insert(hkey) {
                 new_holders.push(HolderDetection {
                     holder: h,
@@ -2837,9 +2842,9 @@ fn merge_multiline_obfuscated_name_year_copyright_pairs(
         };
         let mut updated = false;
         for c in copyrights.iter_mut() {
-            if c.start_line == ln1 && c.end_line == ln1 && c.copyright.contains(name1) {
+            if c.start_line.get() == ln1 && c.end_line.get() == ln1 && c.copyright.contains(name1) {
                 c.copyright = refined.clone();
-                c.end_line = ln2;
+                c.end_line = LineNumber::new(ln2).expect("valid");
                 updated = true;
                 break;
             }
@@ -2847,26 +2852,26 @@ fn merge_multiline_obfuscated_name_year_copyright_pairs(
         if !updated {
             copyrights.push(CopyrightDetection {
                 copyright: refined.clone(),
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
 
         let combined_holder_raw = format!("{name1}, {name2}");
         if let Some(h) = refine_holder_in_copyright_context(&combined_holder_raw) {
             holders.retain(|x| {
-                !(x.start_line == ln1
-                    && x.end_line == ln1
+                !(x.start_line.get() == ln1
+                    && x.end_line.get() == ln1
                     && (x.holder == name1 || x.holder.contains(name1)))
             });
             if !holders
                 .iter()
-                .any(|x| x.start_line == ln1 && x.end_line == ln2 && x.holder == h)
+                .any(|x| x.start_line.get() == ln1 && x.end_line.get() == ln2 && x.holder == h)
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln1,
-                    end_line: ln2,
+                    start_line: LineNumber::new(ln1).expect("valid"),
+                    end_line: LineNumber::new(ln2).expect("valid"),
                 });
             }
         }
@@ -2893,7 +2898,7 @@ fn extend_copyrights_with_next_line_parenthesized_obfuscated_email(
     });
 
     for c in copyrights.iter_mut() {
-        if c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             continue;
         }
 
@@ -2905,7 +2910,7 @@ fn extend_copyrights_with_next_line_parenthesized_obfuscated_email(
             continue;
         }
 
-        let prepared_next = match prepared_cache.get(c.end_line + 1) {
+        let prepared_next = match prepared_cache.get(c.end_line.get() + 1) {
             Some(p) => p,
             None => continue,
         };
@@ -2920,7 +2925,7 @@ fn extend_copyrights_with_next_line_parenthesized_obfuscated_email(
         };
 
         c.copyright = refined;
-        c.end_line += 1;
+        c.end_line += 1usize;
     }
 }
 
@@ -2938,7 +2943,7 @@ fn extend_copyrights_with_following_all_rights_reserved_line(
         LazyLock::new(|| Regex::new(r"(?i)^\s*(?:copyright\b|\(c\))").unwrap());
 
     for c in copyrights.iter_mut() {
-        if c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             continue;
         }
 
@@ -2952,7 +2957,7 @@ fn extend_copyrights_with_following_all_rights_reserved_line(
             continue;
         }
 
-        let Some(next_raw) = raw_lines.get(c.end_line) else {
+        let Some(next_raw) = raw_lines.get(c.end_line.get()) else {
             continue;
         };
         let next_trim = next_raw.trim().trim_start_matches('*').trim_start();
@@ -2968,7 +2973,7 @@ fn extend_copyrights_with_following_all_rights_reserved_line(
         } else {
             merged_normalized
         };
-        c.end_line += 1;
+        c.end_line += 1usize;
     }
 }
 
@@ -2982,11 +2987,11 @@ fn add_modify_suffix_holders(
 
     let mut existing: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for h in holders.clone() {
-        let idx = h.end_line + 1;
+        let idx = h.end_line.get() + 1;
         let Some(next) = prepared_cache.get(idx) else {
             continue;
         };
@@ -3008,7 +3013,7 @@ fn add_modify_suffix_holders(
             continue;
         }
         let combined = normalize_whitespace(&format!("{} {t}", h.holder));
-        let key = (h.start_line, h.end_line + 1, combined.clone());
+        let key = (h.start_line.get(), h.end_line.get() + 1, combined.clone());
         if existing.insert(key) {
             holders.push(HolderDetection {
                 holder: combined,
@@ -3039,7 +3044,7 @@ fn drop_shadowed_c_sign_variants(copyrights: &mut Vec<CopyrightDetection>) {
     for c in copyrights.iter() {
         if contains_c_sign(&c.copyright) {
             with_c_by_span
-                .entry((c.start_line, c.end_line))
+                .entry((c.start_line.get(), c.end_line.get()))
                 .or_default()
                 .insert(canonical_without_c_sign(&c.copyright));
         }
@@ -3052,7 +3057,7 @@ fn drop_shadowed_c_sign_variants(copyrights: &mut Vec<CopyrightDetection>) {
         if contains_c_sign(&c.copyright) {
             return true;
         }
-        let Some(set) = with_c_by_span.get(&(c.start_line, c.end_line)) else {
+        let Some(set) = with_c_by_span.get(&(c.start_line.get(), c.end_line.get())) else {
             return true;
         };
         let canon = canonical_without_c_sign(&c.copyright);
@@ -3070,7 +3075,7 @@ fn drop_shadowed_year_prefixed_holders(holders: &mut Vec<HolderDetection>) {
     let mut by_span: HashMap<(usize, usize), HashSet<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .insert(normalize_whitespace(&h.holder));
     }
@@ -3091,7 +3096,7 @@ fn drop_shadowed_year_prefixed_holders(holders: &mut Vec<HolderDetection>) {
     }
 
     holders.retain(|h| {
-        let Some(set) = by_span.get(&(h.start_line, h.end_line)) else {
+        let Some(set) = by_span.get(&(h.start_line.get(), h.end_line.get())) else {
             return true;
         };
         let normalized = normalize_whitespace(&h.holder);
@@ -3115,7 +3120,7 @@ fn drop_shadowed_for_clause_holders_with_email_copyrights(
     let mut spans_with_email: HashSet<(usize, usize)> = HashSet::new();
     for c in copyrights {
         if c.copyright.contains('@') {
-            spans_with_email.insert((c.start_line, c.end_line));
+            spans_with_email.insert((c.start_line.get(), c.end_line.get()));
         }
     }
     if spans_with_email.is_empty() {
@@ -3125,13 +3130,13 @@ fn drop_shadowed_for_clause_holders_with_email_copyrights(
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .push(h.holder.clone());
     }
 
     holders.retain(|h| {
-        let span = (h.start_line, h.end_line);
+        let span = (h.start_line.get(), h.end_line.get());
         if !spans_with_email.contains(&span) {
             return true;
         }
@@ -3177,11 +3182,11 @@ fn drop_shadowed_multiline_prefix_copyrights(copyrights: &mut Vec<CopyrightDetec
 
     let all: Vec<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
 
     copyrights.retain(|c| {
-        if c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             return true;
         }
         let short = c.copyright.as_str();
@@ -3190,8 +3195,8 @@ fn drop_shadowed_multiline_prefix_copyrights(copyrights: &mut Vec<CopyrightDetec
         }
 
         !all.iter().any(|(s, e, other)| {
-            *s == c.start_line
-                && *e > c.end_line
+            *s == c.start_line.get()
+                && *e > c.end_line.get()
                 && other.len() > short.len()
                 && other.starts_with(short)
                 && other
@@ -3209,11 +3214,11 @@ fn drop_shadowed_multiline_prefix_holders(holders: &mut Vec<HolderDetection>) {
 
     let all: Vec<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     holders.retain(|h| {
-        if h.start_line != h.end_line {
+        if h.start_line.get() != h.end_line.get() {
             return true;
         }
         let short = h.holder.as_str();
@@ -3222,8 +3227,8 @@ fn drop_shadowed_multiline_prefix_holders(holders: &mut Vec<HolderDetection>) {
         }
 
         !all.iter().any(|(s, e, other)| {
-            *s == h.start_line
-                && *e > h.end_line
+            *s == h.start_line.get()
+                && *e > h.end_line.get()
                 && other.len() > short.len()
                 && other.starts_with(short)
                 && {
@@ -3252,7 +3257,7 @@ fn replace_holders_with_embedded_c_year_markers(
     let mut to_add: Vec<HolderDetection> = Vec::new();
     let mut seen: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     holders.retain(|h| {
@@ -3260,12 +3265,11 @@ fn replace_holders_with_embedded_c_year_markers(
             return true;
         }
 
-        for c in copyrights
-            .iter()
-            .filter(|c| c.start_line == h.start_line && c.end_line == h.end_line)
-        {
+        for c in copyrights.iter().filter(|c| {
+            c.start_line.get() == h.start_line.get() && c.end_line.get() == h.end_line.get()
+        }) {
             if let Some(derived) = derive_holder_from_simple_copyright_string(&c.copyright) {
-                let key = (h.start_line, h.end_line, derived.clone());
+                let key = (h.start_line.get(), h.end_line.get(), derived.clone());
                 if seen.insert(key) {
                     to_add.push(HolderDetection {
                         holder: derived,
@@ -3303,7 +3307,7 @@ fn extend_year_only_copyrights_with_trailing_text(
 
     let mut seen_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for c in copyrights.iter_mut() {
@@ -3311,7 +3315,7 @@ fn extend_year_only_copyrights_with_trailing_text(
             continue;
         }
 
-        let Some(prepared) = prepared_cache.get(c.start_line) else {
+        let Some(prepared) = prepared_cache.get(c.start_line.get()) else {
             continue;
         };
         let line = prepared.trim();
@@ -3335,7 +3339,7 @@ fn extend_year_only_copyrights_with_trailing_text(
         c.copyright = refined.clone();
 
         if let Some(h) = refine_holder_in_copyright_context(tail) {
-            let key = (c.start_line, c.end_line, h.clone());
+            let key = (c.start_line.get(), c.end_line.get(), h.clone());
             if seen_h.insert(key) {
                 holders.push(HolderDetection {
                     holder: h,
@@ -3365,11 +3369,11 @@ fn extract_licensed_material_of_company_bare_c_year_lines(
 
     let mut seen_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.raw_line_count() {
@@ -3398,8 +3402,8 @@ fn extract_licensed_material_of_company_bare_c_year_lines(
         if seen_c.insert(ckey) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -3408,14 +3412,16 @@ fn extract_licensed_material_of_company_bare_c_year_lines(
             if seen_h.insert(hkey) {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
 
         copyrights.retain(|c| {
-            !(c.start_line == ln && c.end_line == ln && c.copyright == format!("(c) {year}"))
+            !(c.start_line.get() == ln
+                && c.end_line.get() == ln
+                && c.copyright == format!("(c) {year}"))
         });
     }
 }
@@ -3444,11 +3450,11 @@ fn merge_year_only_copyrights_with_following_author_colon_lines(
 
     let mut seen_c: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     for i in 1..prepared_cache.raw_line_count() {
@@ -3457,7 +3463,7 @@ fn merge_year_only_copyrights_with_following_author_colon_lines(
 
         let Some(prev) = copyrights
             .iter()
-            .find(|c| c.start_line == ln1 && c.end_line == ln1)
+            .find(|c| c.start_line.get() == ln1 && c.end_line.get() == ln1)
         else {
             continue;
         };
@@ -3501,8 +3507,8 @@ fn merge_year_only_copyrights_with_following_author_colon_lines(
         if seen_c.insert(ckey) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
         if let Some(h) = refine_holder_in_copyright_context(name) {
@@ -3510,15 +3516,15 @@ fn merge_year_only_copyrights_with_following_author_colon_lines(
             if seen_h.insert(hkey) {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln1,
-                    end_line: ln2,
+                    start_line: LineNumber::new(ln1).expect("valid"),
+                    end_line: LineNumber::new(ln2).expect("valid"),
                 });
             }
         }
 
         copyrights.retain(|c| {
-            !(c.start_line == ln1
-                && c.end_line == ln1
+            !(c.start_line.get() == ln1
+                && c.end_line.get() == ln1
                 && YEAR_ONLY_COPY_RE.is_match(c.copyright.as_str()))
         });
     }
@@ -3539,11 +3545,11 @@ fn extract_question_mark_year_copyrights(
 
     let mut seen_c: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.len() {
@@ -3567,8 +3573,8 @@ fn extract_question_mark_year_copyrights(
         if seen_c.insert((ln, cr.clone())) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -3578,8 +3584,8 @@ fn extract_question_mark_year_copyrights(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -3726,11 +3732,11 @@ fn extend_copyrights_with_authors_blocks(
 
         for c in copyrights
             .iter_mut()
-            .filter(|c| c.start_line == ln && c.end_line == ln)
+            .filter(|c| c.start_line.get() == ln && c.end_line.get() == ln)
         {
             if c.copyright.starts_with("Copyright") || c.copyright.starts_with("(c)") {
                 c.copyright = extended.clone();
-                c.end_line = end_ln;
+                c.end_line = LineNumber::new(end_ln).expect("valid");
             }
         }
 
@@ -3739,12 +3745,12 @@ fn extend_copyrights_with_authors_blocks(
         {
             holders.push(HolderDetection {
                 holder: h.clone(),
-                start_line: ln,
-                end_line: end_ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(end_ln).expect("valid"),
             });
 
             holders.retain(|hh| {
-                if hh.start_line != ln || hh.end_line != ln {
+                if hh.start_line.get() != ln || hh.end_line.get() != ln {
                     return true;
                 }
                 if hh.holder == h {
@@ -3767,14 +3773,14 @@ fn drop_wider_duplicate_holder_spans(holders: &mut Vec<HolderDetection>) {
         by_text
             .entry(h.holder.clone())
             .or_default()
-            .push((h.start_line, h.end_line));
+            .push((h.start_line.get(), h.end_line.get()));
     }
 
     holders.retain(|h| {
         let Some(spans) = by_text.get(&h.holder) else {
             return true;
         };
-        let (s, e) = (h.start_line, h.end_line);
+        let (s, e) = (h.start_line.get(), h.end_line.get());
         !spans
             .iter()
             .any(|(os, oe)| (*os, *oe) != (s, e) && *os >= s && *oe <= e && (*os > s || *oe < e))
@@ -3819,8 +3825,8 @@ fn apply_openoffice_org_report_builder_bin_normalizations(
         if let Some(cr) = refine_copyright(want_cr) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -3829,8 +3835,8 @@ fn apply_openoffice_org_report_builder_bin_normalizations(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -3888,16 +3894,16 @@ fn extract_midline_c_year_holder_with_leading_acronym(
 
         copyrights.push(CopyrightDetection {
             copyright: cr,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
 
         let holder_raw = format!("{holder} {prefix}");
         if let Some(h) = refine_holder_in_copyright_context(&holder_raw) {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -3908,7 +3914,7 @@ fn dedupe_exact_span_copyrights(copyrights: &mut Vec<CopyrightDetection>) {
         return;
     }
     let mut seen: HashSet<(usize, usize, String)> = HashSet::new();
-    copyrights.retain(|c| seen.insert((c.start_line, c.end_line, c.copyright.clone())));
+    copyrights.retain(|c| seen.insert((c.start_line.get(), c.end_line.get(), c.copyright.clone())));
 }
 
 fn dedupe_exact_span_holders(holders: &mut Vec<HolderDetection>) {
@@ -3916,7 +3922,7 @@ fn dedupe_exact_span_holders(holders: &mut Vec<HolderDetection>) {
         return;
     }
     let mut seen: HashSet<(usize, usize, String)> = HashSet::new();
-    holders.retain(|h| seen.insert((h.start_line, h.end_line, h.holder.clone())));
+    holders.retain(|h| seen.insert((h.start_line.get(), h.end_line.get(), h.holder.clone())));
 }
 
 fn dedupe_exact_span_authors(authors: &mut Vec<AuthorDetection>) {
@@ -3924,7 +3930,7 @@ fn dedupe_exact_span_authors(authors: &mut Vec<AuthorDetection>) {
         return;
     }
     let mut seen: HashSet<(usize, usize, String)> = HashSet::new();
-    authors.retain(|a| seen.insert((a.start_line, a.end_line, a.author.clone())));
+    authors.retain(|a| seen.insert((a.start_line.get(), a.end_line.get(), a.author.clone())));
 }
 
 fn drop_shadowed_prefix_bare_c_copyrights_same_span(copyrights: &mut Vec<CopyrightDetection>) {
@@ -3937,13 +3943,13 @@ fn drop_shadowed_prefix_bare_c_copyrights_same_span(copyrights: &mut Vec<Copyrig
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for c in copyrights.iter() {
         by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .push(c.copyright.clone());
     }
 
     copyrights.retain(|c| {
-        let Some(group) = by_span.get(&(c.start_line, c.end_line)) else {
+        let Some(group) = by_span.get(&(c.start_line.get(), c.end_line.get())) else {
             return true;
         };
         let short = c.copyright.trim();
@@ -3975,13 +3981,13 @@ fn drop_shadowed_acronym_extended_holders(holders: &mut Vec<HolderDetection>) {
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .push(h.holder.clone());
     }
 
     holders.retain(|h| {
-        let Some(group) = by_span.get(&(h.start_line, h.end_line)) else {
+        let Some(group) = by_span.get(&(h.start_line.get(), h.end_line.get())) else {
             return true;
         };
         let candidate = h.holder.trim();
@@ -4123,21 +4129,21 @@ fn extend_multiline_copyright_c_no_year_names(
 
         for c in copyrights
             .iter_mut()
-            .filter(|c| c.start_line == *start_ln && !YEAR_RE.is_match(c.copyright.as_str()))
+            .filter(|c| c.start_line.get() == *start_ln && !YEAR_RE.is_match(c.copyright.as_str()))
         {
             if refined.len() > c.copyright.len() && refined.starts_with(&c.copyright) {
                 c.copyright = refined.clone();
-                c.end_line = end_ln;
+                c.end_line = LineNumber::new(end_ln).expect("valid");
             }
         }
 
         for h in holders
             .iter_mut()
-            .filter(|h| h.start_line == *start_ln && !YEAR_RE.is_match(h.holder.as_str()))
+            .filter(|h| h.start_line.get() == *start_ln && !YEAR_RE.is_match(h.holder.as_str()))
         {
             if refined_holder.len() > h.holder.len() && refined_holder.starts_with(&h.holder) {
                 h.holder = refined_holder.clone();
-                h.end_line = end_ln;
+                h.end_line = LineNumber::new(end_ln).expect("valid");
             }
         }
     }
@@ -4241,22 +4247,27 @@ fn extend_multiline_copyright_c_year_holder_continuations(
         };
 
         let mut updated_copyright = false;
-        for c in copyrights.iter_mut().filter(|c| c.start_line == *start_ln) {
+        for c in copyrights
+            .iter_mut()
+            .filter(|c| c.start_line.get() == *start_ln)
+        {
             if refined.len() > c.copyright.len() && refined.starts_with(&c.copyright) {
                 c.copyright = refined.clone();
-                c.end_line = end_ln;
+                c.end_line = LineNumber::new(end_ln).expect("valid");
                 updated_copyright = true;
             }
         }
         if !updated_copyright
             && !copyrights.iter().any(|c| {
-                c.start_line == *start_ln && c.end_line == end_ln && c.copyright == refined
+                c.start_line.get() == *start_ln
+                    && c.end_line.get() == end_ln
+                    && c.copyright == refined
             })
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined.clone(),
-                start_line: *start_ln,
-                end_line: end_ln,
+                start_line: LineNumber::new(*start_ln).expect("invalid line number"),
+                end_line: LineNumber::new(end_ln).expect("valid"),
             });
         }
 
@@ -4265,22 +4276,27 @@ fn extend_multiline_copyright_c_year_holder_continuations(
         };
 
         let mut updated_holder = false;
-        for h in holders.iter_mut().filter(|h| h.start_line == *start_ln) {
+        for h in holders
+            .iter_mut()
+            .filter(|h| h.start_line.get() == *start_ln)
+        {
             if refined_holder.len() > h.holder.len() && refined_holder.starts_with(&h.holder) {
                 h.holder = refined_holder.clone();
-                h.end_line = end_ln;
+                h.end_line = LineNumber::new(end_ln).expect("valid");
                 updated_holder = true;
             }
         }
         if !updated_holder
             && !holders.iter().any(|h| {
-                h.start_line == *start_ln && h.end_line == end_ln && h.holder == refined_holder
+                h.start_line.get() == *start_ln
+                    && h.end_line.get() == end_ln
+                    && h.holder == refined_holder
             })
         {
             holders.push(HolderDetection {
                 holder: refined_holder,
-                start_line: *start_ln,
-                end_line: end_ln,
+                start_line: LineNumber::new(*start_ln).expect("invalid line number"),
+                end_line: LineNumber::new(end_ln).expect("valid"),
             });
         }
     }
@@ -4334,18 +4350,18 @@ fn extend_authors_see_url_copyrights(
         };
         let refined_holder = derive_holder_from_simple_copyright_string(&format!("{prefix} see"));
 
-        for c in copyrights.iter_mut().filter(|c| c.start_line == *ln1) {
+        for c in copyrights.iter_mut().filter(|c| c.start_line.get() == *ln1) {
             if refined.len() > c.copyright.len() && refined.starts_with(&c.copyright) {
                 c.copyright = refined.clone();
-                c.end_line = *ln2;
+                c.end_line = LineNumber::new(*ln2).expect("valid");
             }
         }
 
         if let Some(refined_holder) = refined_holder {
-            for h in holders.iter_mut().filter(|h| h.start_line == *ln1) {
+            for h in holders.iter_mut().filter(|h| h.start_line.get() == *ln1) {
                 if refined_holder.len() > h.holder.len() && refined_holder.starts_with(&h.holder) {
                     h.holder = refined_holder.clone();
-                    h.end_line = *ln2;
+                    h.end_line = LineNumber::new(*ln2).expect("valid");
                 }
             }
         }
@@ -4368,7 +4384,7 @@ fn extend_leading_dash_suffixes(
             continue;
         }
 
-        let has_copyright_on_line1 = copyrights.iter().any(|c| c.start_line == *ln1);
+        let has_copyright_on_line1 = copyrights.iter().any(|c| c.start_line.get() == *ln1);
         if !has_copyright_on_line1 {
             continue;
         }
@@ -4404,7 +4420,7 @@ fn extend_leading_dash_suffixes(
 
         let suffix = format!("- {tail}");
 
-        for c in copyrights.iter_mut().filter(|c| c.start_line == *ln1) {
+        for c in copyrights.iter_mut().filter(|c| c.start_line.get() == *ln1) {
             if c.copyright.contains(&suffix) {
                 continue;
             }
@@ -4413,21 +4429,21 @@ fn extend_leading_dash_suffixes(
                 .filter(|r| r.contains(tail))
                 .unwrap_or(extended);
             c.copyright = refined;
-            c.end_line = *ln2;
+            c.end_line = LineNumber::new(*ln2).expect("valid");
         }
 
         let derived: Option<String> = copyrights
             .iter()
-            .find(|c| c.start_line == *ln1)
+            .find(|c| c.start_line.get() == *ln1)
             .and_then(|c| derive_holder_from_simple_copyright_string(&c.copyright));
 
-        for h in holders.iter_mut().filter(|h| h.start_line == *ln1) {
+        for h in holders.iter_mut().filter(|h| h.start_line.get() == *ln1) {
             if let Some(ref d) = derived
                 && d.len() >= h.holder.len()
                 && d.contains(tail)
             {
                 h.holder = d.clone();
-                h.end_line = *ln2;
+                h.end_line = LineNumber::new(*ln2).expect("valid");
                 continue;
             }
 
@@ -4440,10 +4456,10 @@ fn extend_leading_dash_suffixes(
                 && refined.contains(tail)
             {
                 h.holder = refined;
-                h.end_line = *ln2;
+                h.end_line = LineNumber::new(*ln2).expect("valid");
             } else {
                 h.holder = extended;
-                h.end_line = *ln2;
+                h.end_line = LineNumber::new(*ln2).expect("valid");
             }
         }
     }
@@ -4468,12 +4484,12 @@ fn extend_dash_obfuscated_email_suffixes(
     });
 
     for (ln, _) in group {
-        if !copyrights.iter().any(|c| c.start_line == *ln) {
+        if !copyrights.iter().any(|c| c.start_line.get() == *ln) {
             continue;
         }
 
         let has_named_holder = holders.iter().any(|h| {
-            h.start_line == *ln
+            h.start_line.get() == *ln
                 && !h.holder.to_ascii_lowercase().contains(" at ")
                 && !h.holder.to_ascii_lowercase().contains(" dot ")
         });
@@ -4496,7 +4512,7 @@ fn extend_dash_obfuscated_email_suffixes(
 
         let obfuscated = format!("{user} at {host} dot {tld}");
 
-        for c in copyrights.iter_mut().filter(|c| c.start_line == *ln) {
+        for c in copyrights.iter_mut().filter(|c| c.start_line.get() == *ln) {
             if c.copyright.contains(&obfuscated) {
                 continue;
             }
@@ -4527,7 +4543,7 @@ fn extend_trailing_copy_year_suffixes(
 
         for c in copyrights
             .iter_mut()
-            .filter(|c| c.start_line == *ln && c.end_line == *ln)
+            .filter(|c| c.start_line.get() == *ln && c.end_line.get() == *ln)
         {
             let lower = c.copyright.to_ascii_lowercase();
             if !lower.starts_with("copyright") {
@@ -4566,27 +4582,29 @@ fn extend_w3c_registered_org_list_suffixes(
 
         for c in copyrights
             .iter_mut()
-            .filter(|c| c.start_line == *ln || c.start_line + 1 == *ln)
+            .filter(|c| c.start_line.get() == *ln || c.start_line.get() + 1 == *ln)
         {
             if c.copyright.contains(&full) {
                 continue;
             }
             if c.copyright.contains("W3C(r)") {
                 c.copyright = c.copyright.replace("W3C(r)", &full);
-                c.end_line = c.end_line.max(*ln);
+                c.end_line =
+                    LineNumber::new(c.end_line.get().max(*ln)).expect("invalid line number");
             }
         }
 
         for h in holders
             .iter_mut()
-            .filter(|h| h.start_line == *ln || h.start_line + 1 == *ln)
+            .filter(|h| h.start_line.get() == *ln || h.start_line.get() + 1 == *ln)
         {
             if h.holder.contains(&full) {
                 continue;
             }
             if h.holder == "W3C(r)" {
                 h.holder = full.clone();
-                h.end_line = h.end_line.max(*ln);
+                h.end_line =
+                    LineNumber::new(h.end_line.get().max(*ln)).expect("invalid line number");
             }
         }
     }
@@ -4612,7 +4630,9 @@ fn drop_symbol_year_only_copyrights(content: &str, copyrights: &mut Vec<Copyrigh
             continue;
         }
         let to_drop = format!("Copyright (c) {year}");
-        copyrights.retain(|c| !(c.start_line == ln && c.end_line == ln && c.copyright == to_drop));
+        copyrights.retain(|c| {
+            !(c.start_line.get() == ln && c.end_line.get() == ln && c.copyright == to_drop)
+        });
     }
 }
 
@@ -4652,7 +4672,7 @@ fn merge_multiline_copyrighted_by_with_trailing_copyright_clause(
         if let Some(refined) = refine_copyright(&candidate) {
             let ln = cap
                 .get(0)
-                .map(|m| line_number_index.line_number_at_offset(m.start()))
+                .map(|m| line_number_index.line_number_at_offset(m.start()).get())
                 .unwrap_or(1);
             unique_clauses.insert(refined.clone());
             clause_max_line
@@ -4689,7 +4709,8 @@ fn merge_multiline_copyrighted_by_with_trailing_copyright_clause(
         } else {
             det.copyright = merged;
         }
-        det.end_line = det.end_line.max(suffix_line);
+        det.end_line =
+            LineNumber::new(det.end_line.get().max(suffix_line)).expect("invalid line number");
     }
 }
 
@@ -4785,8 +4806,8 @@ fn merge_freebird_c_inc_urls(
         {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
         let holder_raw = "Inc.";
@@ -4795,8 +4816,8 @@ fn merge_freebird_c_inc_urls(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -4840,7 +4861,7 @@ fn merge_debugging390_best_viewed_suffix(
         };
 
         copyrights.retain(|c| {
-            !(c.start_line == ln
+            !(c.start_line.get() == ln
                 && c.copyright.contains(who)
                 && c.copyright.contains("2000-2001")
                 && !c.copyright.ends_with("Best"))
@@ -4848,18 +4869,18 @@ fn merge_debugging390_best_viewed_suffix(
         if !copyrights.iter().any(|c| c.copyright == merged) {
             copyrights.push(CopyrightDetection {
                 copyright: merged,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
 
         let holder_raw = format!("{who} Best");
-        holders.retain(|h| !(h.start_line == ln && h.holder == who));
+        holders.retain(|h| !(h.start_line.get() == ln && h.holder == who));
         if let Some(h) = refine_holder_in_copyright_context(&holder_raw) {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
     }
@@ -4906,8 +4927,8 @@ fn merge_fsf_gdb_notice_lines(
         if !copyrights.iter().any(|c| c.copyright == merged) {
             copyrights.push(CopyrightDetection {
                 copyright: merged,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
 
@@ -4915,8 +4936,8 @@ fn merge_fsf_gdb_notice_lines(
         if !holders.iter().any(|x| x.holder == holder) {
             holders.push(HolderDetection {
                 holder: holder.to_string(),
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
     }
@@ -4953,23 +4974,23 @@ fn merge_axis_ethereal_suffix(
             continue;
         };
 
-        copyrights.retain(|c| !(c.start_line == ln && c.copyright == p1));
+        copyrights.retain(|c| !(c.start_line.get() == ln && c.copyright == p1));
         if !copyrights.iter().any(|c| c.copyright == merged) {
             copyrights.push(CopyrightDetection {
                 copyright: merged,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
 
-        holders.retain(|h| !(h.start_line == ln && h.holder == "Axis Communications AB"));
+        holders.retain(|h| !(h.start_line.get() == ln && h.holder == "Axis Communications AB"));
         if let Some(h) = refine_holder_in_copyright_context("Axis Communications AB Ethereal")
             && !holders.iter().any(|x| x.holder == h)
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
     }
@@ -5020,8 +5041,8 @@ fn merge_kirkwood_converted_to(
         {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
         let holder_raw = format!("{who} Converted");
@@ -5030,8 +5051,8 @@ fn merge_kirkwood_converted_to(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
     }
@@ -5181,8 +5202,8 @@ fn extract_line_ending_copyright_then_by_holder(
                 {
                     copyrights.push(CopyrightDetection {
                         copyright: copyright_text,
-                        start_line: ln,
-                        end_line: next_ln,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(next_ln).expect("valid"),
                     });
                 }
 
@@ -5191,8 +5212,8 @@ fn extract_line_ending_copyright_then_by_holder(
                 {
                     holders.push(HolderDetection {
                         holder,
-                        start_line: next_ln,
-                        end_line: next_ln,
+                        start_line: LineNumber::new(next_ln).expect("valid"),
+                        end_line: LineNumber::new(next_ln).expect("valid"),
                     });
                 }
             }
@@ -5206,7 +5227,7 @@ fn drop_trailing_software_line_from_holders(
     holders: &mut [HolderDetection],
 ) {
     for h in holders.iter_mut() {
-        if h.end_line <= h.start_line {
+        if h.end_line.get() <= h.start_line.get() {
             continue;
         }
 
@@ -5214,7 +5235,7 @@ fn drop_trailing_software_line_from_holders(
             continue;
         }
 
-        let Some(prepared) = prepared_cache.get(h.end_line) else {
+        let Some(prepared) = prepared_cache.get(h.end_line.get()) else {
             continue;
         };
         let prepared_lower = prepared.trim().to_ascii_lowercase();
@@ -5325,23 +5346,23 @@ fn recover_template_literal_year_range_copyrights(
         if seen_copyrights.insert(copyright_text.clone()) {
             copyrights.push(CopyrightDetection {
                 copyright: copyright_text,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
         let truncated = format!("Copyright {start}-$");
         copyrights.retain(|c| {
-            !(c.start_line == ln
-                && c.end_line == ln
+            !(c.start_line.get() == ln
+                && c.end_line.get() == ln
                 && c.copyright.eq_ignore_ascii_case(&truncated))
         });
 
         if seen_holders.insert(holder.clone()) {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -5380,14 +5401,20 @@ fn drop_url_embedded_suffix_variants_same_span(
                     || tail.starts_with("url ")
                     || tail.starts_with("http")
                 {
-                    drop.insert((longer.start_line, longer.end_line, longer.copyright.clone()));
+                    drop.insert((
+                        longer.start_line.get(),
+                        longer.end_line.get(),
+                        longer.copyright.clone(),
+                    ));
                     break;
                 }
             }
         }
 
         if !drop.is_empty() {
-            copyrights.retain(|c| !drop.contains(&(c.start_line, c.end_line, c.copyright.clone())));
+            copyrights.retain(|c| {
+                !drop.contains(&(c.start_line.get(), c.end_line.get(), c.copyright.clone()))
+            });
         }
     }
 
@@ -5423,14 +5450,20 @@ fn drop_url_embedded_suffix_variants_same_span(
                     || tail.starts_with("url ")
                     || tail.starts_with("http")
                 {
-                    drop.insert((longer.start_line, longer.end_line, longer.holder.clone()));
+                    drop.insert((
+                        longer.start_line.get(),
+                        longer.end_line.get(),
+                        longer.holder.clone(),
+                    ));
                     break;
                 }
             }
         }
 
         if !drop.is_empty() {
-            holders.retain(|h| !drop.contains(&(h.start_line, h.end_line, h.holder.clone())));
+            holders.retain(|h| {
+                !drop.contains(&(h.start_line.get(), h.end_line.get(), h.holder.clone()))
+            });
         }
     }
 }
@@ -5498,8 +5531,8 @@ fn extract_following_authors_holders(
             if seen.insert(holder.clone()) {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: ln,
-                    end_line: end_ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(end_ln).expect("valid"),
                 });
             }
         }
@@ -5543,10 +5576,10 @@ fn drop_created_by_camelcase_identifier_authors(
     }
 
     authors.retain(|author| {
-        if author.start_line != author.end_line {
+        if author.start_line.get() != author.end_line.get() {
             return true;
         }
-        let Some(names) = by_line.get(&author.start_line) else {
+        let Some(names) = by_line.get(&author.start_line.get()) else {
             return true;
         };
 
@@ -5646,7 +5679,7 @@ fn merge_implemented_by_lines(
         let cr_first = cr.split_whitespace().next().unwrap_or("");
 
         for det in copyrights.iter_mut() {
-            if det.start_line == ln
+            if det.start_line.get() == ln
                 && det.copyright.starts_with("Copyright (c)")
                 && det.copyright.contains(",")
                 && det.copyright.contains(cr_first)
@@ -5657,21 +5690,24 @@ fn merge_implemented_by_lines(
         if !copyrights.iter().any(|c| c.copyright == cr) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
 
         holders.retain(|h| {
-            !(h.start_line == ln && h.holder == holder_raw.trim_end_matches(" Implemented by"))
+            !(h.start_line.get() == ln
+                && h.holder == holder_raw.trim_end_matches(" Implemented by"))
         });
         if let Some(h) = refine_holder(&holder_raw)
-            && !holders.iter().any(|x| x.holder == h && x.start_line == ln)
+            && !holders
+                .iter()
+                .any(|x| x.holder == h && x.start_line.get() == ln)
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
 
@@ -5718,14 +5754,14 @@ fn split_written_by_copyrights_into_holder_prefixed_clauses(
             };
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
             if let Some(h) = refine_holder(name) {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
             added_any = true;
@@ -5791,8 +5827,8 @@ fn fix_shm_inline_copyrights(
         if seen_c.insert(cr.clone()) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -5801,8 +5837,8 @@ fn fix_shm_inline_copyrights(
         {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
         break;
@@ -5840,16 +5876,16 @@ fn fix_n_tty_linus_torvalds_written_by_clause(
         if seen_c.insert(cr.clone()) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
         let holder = "Linus Torvalds".to_string();
         if seen_h.insert(holder.clone()) {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln,
-                end_line: ln + 1,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln + 1).expect("invalid line number"),
             });
         }
         break;
@@ -5922,15 +5958,15 @@ fn fix_sundry_contributors_truncation(
     if !copyrights.iter().any(|c| c.copyright == full_cr) {
         copyrights.push(CopyrightDetection {
             copyright: full_cr,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
     }
     if !holders.iter().any(|h| h.holder == full_holder) {
         holders.push(HolderDetection {
             holder: full_holder,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
     }
 }
@@ -5990,7 +6026,7 @@ fn split_embedded_copyright_detections(
             for cut in splits {
                 let part = s[start..cut].trim();
                 if let Some(refined) = refine_copyright(part)
-                    && seen.insert((det.start_line, det.end_line, refined.clone()))
+                    && seen.insert((det.start_line.get(), det.end_line.get(), refined.clone()))
                 {
                     let d = CopyrightDetection {
                         copyright: refined,
@@ -6005,7 +6041,7 @@ fn split_embedded_copyright_detections(
 
             let tail = s[start..].trim();
             if let Some(refined) = refine_copyright(tail)
-                && seen.insert((det.start_line, det.end_line, refined.clone()))
+                && seen.insert((det.start_line.get(), det.end_line.get(), refined.clone()))
             {
                 let d = CopyrightDetection {
                     copyright: refined,
@@ -6028,7 +6064,7 @@ fn split_embedded_copyright_detections(
             for cut in cuts {
                 let part = s[start..cut].trim();
                 if let Some(refined) = refine_copyright(part)
-                    && seen.insert((det.start_line, det.end_line, refined.clone()))
+                    && seen.insert((det.start_line.get(), det.end_line.get(), refined.clone()))
                 {
                     let d = CopyrightDetection {
                         copyright: refined,
@@ -6043,7 +6079,7 @@ fn split_embedded_copyright_detections(
 
             let tail = s[start..].trim().trim_start_matches(',').trim();
             if let Some(refined) = refine_copyright(tail)
-                && seen.insert((det.start_line, det.end_line, refined.clone()))
+                && seen.insert((det.start_line.get(), det.end_line.get(), refined.clone()))
             {
                 let d = CopyrightDetection {
                     copyright: refined,
@@ -6056,7 +6092,7 @@ fn split_embedded_copyright_detections(
             continue;
         }
 
-        if seen.insert((det.start_line, det.end_line, s.clone())) {
+        if seen.insert((det.start_line.get(), det.end_line.get(), s.clone())) {
             out.push(CopyrightDetection {
                 copyright: s,
                 start_line: det.start_line,
@@ -6114,7 +6150,8 @@ fn extend_bare_c_year_detections_to_line_end_for_multi_c_lines(
 
             let mut did_replace = false;
             for det in copyrights.iter_mut() {
-                if det.start_line == ln && det.end_line == ln && det.copyright == short {
+                if det.start_line.get() == ln && det.end_line.get() == ln && det.copyright == short
+                {
                     det.copyright = extended.clone();
                     did_replace = true;
                 }
@@ -6126,12 +6163,12 @@ fn extend_bare_c_year_detections_to_line_end_for_multi_c_lines(
             if let Some(holder) = derive_holder_from_simple_copyright_string(&extended)
                 && !holders
                     .iter()
-                    .any(|h| h.start_line == ln && h.holder == holder)
+                    .any(|h| h.start_line.get() == ln && h.holder == holder)
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -6264,10 +6301,10 @@ fn drop_obfuscated_email_year_only_copyrights(
     }
 
     copyrights.retain(|c| {
-        if c.start_line != c.end_line {
+        if c.start_line.get() != c.end_line.get() {
             return true;
         }
-        let Some(year) = drop.get(&c.start_line) else {
+        let Some(year) = drop.get(&c.start_line.get()) else {
             return true;
         };
         let lower = c.copyright.to_ascii_lowercase();
@@ -6281,10 +6318,10 @@ fn drop_obfuscated_email_year_only_copyrights(
     });
 
     holders.retain(|h| {
-        if h.start_line != h.end_line {
+        if h.start_line.get() != h.end_line.get() {
             return true;
         }
-        if !drop.contains_key(&h.start_line) {
+        if !drop.contains_key(&h.start_line.get()) {
             return true;
         }
         let lower = h.holder.to_ascii_lowercase();
@@ -6307,8 +6344,8 @@ fn extract_glide_3dfx_copyright_notice(content: &str, copyrights: &mut Vec<Copyr
             {
                 copyrights.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -6327,7 +6364,7 @@ fn extract_spdx_filecopyrighttext_c_without_year(
     let mut seen_cr: HashSet<String> = copyrights.iter().map(|c| c.copyright.clone()).collect();
     let mut seen_h: HashSet<(String, usize)> = holders
         .iter()
-        .map(|h| (h.holder.clone(), h.start_line))
+        .map(|h| (h.holder.clone(), h.start_line.get()))
         .collect();
 
     for (idx, line) in content.lines().enumerate() {
@@ -6347,8 +6384,8 @@ fn extract_spdx_filecopyrighttext_c_without_year(
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -6357,8 +6394,8 @@ fn extract_spdx_filecopyrighttext_c_without_year(
         {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -6389,7 +6426,7 @@ fn extract_html_meta_name_copyright_content(
     let mut seen_cr: HashSet<String> = copyrights.iter().map(|c| c.copyright.clone()).collect();
     let mut seen_h: HashSet<(String, usize)> = holders
         .iter()
-        .map(|h| (h.holder.clone(), h.start_line))
+        .map(|h| (h.holder.clone(), h.start_line.get()))
         .collect();
 
     for (idx, line) in content.lines().enumerate() {
@@ -6416,8 +6453,8 @@ fn extract_html_meta_name_copyright_content(
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined.clone(),
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
 
             if let Some(holder) = derive_holder_from_simple_copyright_string(&refined)
@@ -6425,8 +6462,8 @@ fn extract_html_meta_name_copyright_content(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -6448,7 +6485,7 @@ fn extract_added_the_copyright_year_for_lines(
     let mut seen_cr: HashSet<String> = copyrights.iter().map(|c| c.copyright.clone()).collect();
     let mut seen_h: HashSet<(String, usize)> = holders
         .iter()
-        .map(|h| (h.holder.clone(), h.start_line))
+        .map(|h| (h.holder.clone(), h.start_line.get()))
         .collect();
 
     for idx in 0..prepared_cache.len() {
@@ -6470,16 +6507,16 @@ fn extract_added_the_copyright_year_for_lines(
         if seen_cr.insert(cr.clone()) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
         if seen_h.insert((holder.clone(), ln)) {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -6496,7 +6533,7 @@ fn extract_changelog_timestamp_copyrights_from_content(
     let mut seen_cr: HashSet<String> = copyrights.iter().map(|c| c.copyright.clone()).collect();
     let mut seen_h: HashSet<(String, usize)> = holders
         .iter()
-        .map(|h| (h.holder.clone(), h.start_line))
+        .map(|h| (h.holder.clone(), h.start_line.get()))
         .collect();
 
     let mut matches: Vec<(usize, String, String)> = Vec::new();
@@ -6529,8 +6566,8 @@ fn extract_changelog_timestamp_copyrights_from_content(
     {
         copyrights.push(CopyrightDetection {
             copyright: refined,
-            start_line: *ln,
-            end_line: *ln,
+            start_line: LineNumber::new(*ln).expect("invalid line number"),
+            end_line: LineNumber::new(*ln).expect("invalid line number"),
         });
     }
 
@@ -6539,8 +6576,8 @@ fn extract_changelog_timestamp_copyrights_from_content(
     {
         holders.push(HolderDetection {
             holder,
-            start_line: *ln,
-            end_line: *ln,
+            start_line: LineNumber::new(*ln).expect("invalid line number"),
+            end_line: LineNumber::new(*ln).expect("invalid line number"),
         });
     }
 }
@@ -6652,8 +6689,8 @@ fn extract_common_year_only_lines(
         if seen.insert(refined.clone()) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -6740,8 +6777,8 @@ fn extract_embedded_bare_c_year_suffixes(
             if seen.insert(cr_lower) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -6791,8 +6828,8 @@ fn extract_trailing_bare_c_year_range_suffixes(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -6865,8 +6902,8 @@ fn extract_repeated_embedded_bare_c_year_suffixes(
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: first_ln,
-                end_line: first_ln,
+                start_line: LineNumber::new(first_ln).expect("valid"),
+                end_line: LineNumber::new(first_ln).expect("valid"),
             });
         }
     }
@@ -6880,8 +6917,8 @@ fn extract_repeated_embedded_bare_c_year_suffixes(
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: first_ln,
-                end_line: first_ln,
+                start_line: LineNumber::new(first_ln).expect("valid"),
+                end_line: LineNumber::new(first_ln).expect("valid"),
             });
         }
     }
@@ -6923,16 +6960,16 @@ fn extract_lowercase_username_angle_email_copyrights(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
             if seen_holders.insert(user.to_string()) {
                 holders.push(HolderDetection {
                     holder: user.to_string(),
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -6971,16 +7008,16 @@ fn extract_lowercase_username_paren_email_copyrights(
                 {
                     copyrights.push(CopyrightDetection {
                         copyright: cr,
-                        start_line: *ln,
-                        end_line: *ln,
+                        start_line: LineNumber::new(*ln).expect("invalid line number"),
+                        end_line: LineNumber::new(*ln).expect("invalid line number"),
                     });
                 }
 
                 if seen_holders.insert(user.to_string()) {
                     holders.push(HolderDetection {
                         holder: user.to_string(),
-                        start_line: *ln,
-                        end_line: *ln,
+                        start_line: LineNumber::new(*ln).expect("invalid line number"),
+                        end_line: LineNumber::new(*ln).expect("invalid line number"),
                     });
                 }
             }
@@ -7024,8 +7061,8 @@ fn extract_c_year_range_by_name_comma_email_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -7034,8 +7071,8 @@ fn extract_c_year_range_by_name_comma_email_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7085,16 +7122,16 @@ fn extract_copyright_years_by_name_paren_email_lines(
                 if seen_copyrights.insert(full.to_ascii_lowercase()) {
                     copyrights.push(CopyrightDetection {
                         copyright: full.clone(),
-                        start_line: *ln,
-                        end_line: *ln,
+                        start_line: LineNumber::new(*ln).expect("invalid line number"),
+                        end_line: LineNumber::new(*ln).expect("invalid line number"),
                     });
                 }
 
                 let year_only_raw = format!("copyright {years}");
                 if let Some(year_only) = refine_copyright(&year_only_raw) {
                     copyrights.retain(|c| {
-                        !(c.start_line == *ln
-                            && c.end_line == *ln
+                        !(c.start_line.get() == *ln
+                            && c.end_line.get() == *ln
                             && c.copyright == year_only
                             && c.copyright != full)
                     });
@@ -7105,8 +7142,8 @@ fn extract_copyright_years_by_name_paren_email_lines(
                 {
                     holders.push(HolderDetection {
                         holder,
-                        start_line: *ln,
-                        end_line: *ln,
+                        start_line: LineNumber::new(*ln).expect("invalid line number"),
+                        end_line: LineNumber::new(*ln).expect("invalid line number"),
                     });
                 }
             }
@@ -7199,15 +7236,17 @@ fn extract_copyright_years_by_name_then_paren_email_next_line(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: full,
-                    start_line: ln,
-                    end_line: next_ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(next_ln).expect("valid"),
                 });
             }
 
             let year_only_raw = format!("copyright {years}");
             if let Some(year_only) = refine_copyright(&year_only_raw) {
                 copyrights.retain(|c| {
-                    !(c.start_line == ln && c.end_line == ln && c.copyright == year_only)
+                    !(c.start_line.get() == ln
+                        && c.end_line.get() == ln
+                        && c.copyright == year_only)
                 });
             }
 
@@ -7216,8 +7255,8 @@ fn extract_copyright_years_by_name_then_paren_email_next_line(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
 
@@ -7261,8 +7300,8 @@ fn extract_copyright_year_name_with_of_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -7271,8 +7310,8 @@ fn extract_copyright_year_name_with_of_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7385,7 +7424,9 @@ fn extract_standalone_c_holder_year_lines(
             }
 
             let already_covered = copyrights.iter().any(|c| {
-                c.start_line <= *ln && c.end_line >= *ln && c.copyright.contains(&yearish)
+                c.start_line.get() <= *ln
+                    && c.end_line.get() >= *ln
+                    && c.copyright.contains(&yearish)
             });
             if already_covered {
                 continue;
@@ -7426,16 +7467,16 @@ fn extract_standalone_c_holder_year_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
                     end_line: if email_suffix.is_some() {
                         group
                             .iter()
                             .skip(idx + 1)
                             .find(|(_, l)| !l.trim().is_empty())
-                            .map(|(n, _)| *n)
-                            .unwrap_or(*ln)
+                            .map(|(n, _)| LineNumber::new(*n).expect("invalid line number"))
+                            .unwrap_or(LineNumber::new(*ln).expect("invalid line number"))
                     } else {
-                        *ln
+                        LineNumber::new(*ln).expect("invalid line number")
                     },
                 });
             }
@@ -7445,8 +7486,8 @@ fn extract_standalone_c_holder_year_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7509,8 +7550,8 @@ fn extract_c_holder_without_year_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -7519,8 +7560,8 @@ fn extract_c_holder_without_year_lines(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7534,11 +7575,11 @@ fn extract_c_years_then_holder_lines(
 ) {
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for group in groups {
@@ -7584,8 +7625,8 @@ fn extract_c_years_then_holder_lines(
             if seen_cr.insert((*ln, cr.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr.clone(),
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -7594,8 +7635,8 @@ fn extract_c_years_then_holder_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7616,11 +7657,11 @@ fn extract_copyright_c_years_holder_lines(
 
     let mut seen_c: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for group in groups {
@@ -7647,8 +7688,8 @@ fn extract_copyright_c_years_holder_lines(
             if seen_c.insert((*ln, cr.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr.clone(),
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -7657,8 +7698,8 @@ fn extract_copyright_c_years_holder_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -7680,11 +7721,11 @@ fn extract_three_digit_copyright_year_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for idx in 0..prepared_cache.len() {
@@ -7715,8 +7756,8 @@ fn extract_three_digit_copyright_year_lines(
         if seen_cr.insert((ln, refined.clone())) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -7725,8 +7766,8 @@ fn extract_three_digit_copyright_year_lines(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -7747,11 +7788,11 @@ fn extract_copyrighted_by_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for idx in 0..prepared_cache.len() {
@@ -7785,8 +7826,8 @@ fn extract_copyrighted_by_lines(
             if seen_cr.insert((ln, refined.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
 
@@ -7795,8 +7836,8 @@ fn extract_copyrighted_by_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -7818,11 +7859,11 @@ fn extract_c_word_year_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for idx in 0..prepared_cache.len() {
@@ -7862,8 +7903,8 @@ fn extract_c_word_year_lines(
             if seen_cr.insert((ln, refined.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
 
@@ -7872,8 +7913,8 @@ fn extract_c_word_year_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -7898,11 +7939,11 @@ fn extract_are_c_year_holder_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.len() {
@@ -7938,8 +7979,8 @@ fn extract_are_c_year_holder_lines(
             if seen_cr.insert((ln, refined.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
 
@@ -7948,8 +7989,8 @@ fn extract_are_c_year_holder_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -7970,11 +8011,11 @@ fn extract_bare_c_by_holder_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.len() {
@@ -7999,8 +8040,8 @@ fn extract_bare_c_by_holder_lines(
         if seen_cr.insert((ln, refined.clone())) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
         if let Some(h) = refine_holder_in_copyright_context(holder_raw)
@@ -8008,8 +8049,8 @@ fn extract_bare_c_by_holder_lines(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -8031,11 +8072,11 @@ fn extract_all_rights_reserved_by_holder_lines(
 
     let mut seen_cr: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.len() {
@@ -8061,8 +8102,8 @@ fn extract_all_rights_reserved_by_holder_lines(
         if seen_cr.insert((ln, refined.clone())) {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
 
@@ -8071,8 +8112,8 @@ fn extract_all_rights_reserved_by_holder_lines(
         {
             holders.push(HolderDetection {
                 holder: h,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).unwrap(),
+                end_line: LineNumber::new(ln).unwrap(),
             });
         }
     }
@@ -8096,11 +8137,11 @@ fn extract_holder_is_name_paren_email_lines(
 
     let mut seen_c: HashSet<(usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_h: HashSet<(usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.holder.clone()))
         .collect();
 
     for ln in 1..=prepared_cache.len() {
@@ -8124,8 +8165,8 @@ fn extract_holder_is_name_paren_email_lines(
             if seen_c.insert((ln, cr.clone())) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
 
@@ -8134,8 +8175,8 @@ fn extract_holder_is_name_paren_email_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).unwrap(),
+                    end_line: LineNumber::new(ln).unwrap(),
                 });
             }
         }
@@ -8246,8 +8287,8 @@ fn extract_copr_lines(
             if seen_copyrights.insert(cr.clone()) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr.clone(),
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -8276,8 +8317,8 @@ fn extract_copr_lines(
             if seen_holders.insert(h.clone()) {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -8354,7 +8395,7 @@ fn apply_javadoc_company_metadata(
 
     let ln = copy_cap
         .get(0)
-        .map(|m| line_number_index.line_number_at_offset(m.start()))
+        .map(|m| line_number_index.line_number_at_offset(m.start()).get())
         .unwrap_or(1);
 
     let append_company_value = company_val.split_whitespace().count() >= 2;
@@ -8376,16 +8417,16 @@ fn apply_javadoc_company_metadata(
     if !copyrights.iter().any(|c| c.copyright == desired_copyright) {
         copyrights.push(CopyrightDetection {
             copyright: desired_copyright,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
     }
 
     if !holders.iter().any(|h| h.holder == company_holder) {
         holders.push(HolderDetection {
             holder: company_holder,
-            start_line: ln,
-            end_line: ln,
+            start_line: LineNumber::new(ln).unwrap(),
+            end_line: LineNumber::new(ln).unwrap(),
         });
     }
 }
@@ -8515,11 +8556,11 @@ fn normalize_pudn_html_footer_copyrights(
     });
     let mut seen_copyrights: HashSet<(usize, usize, String)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line, c.copyright.clone()))
+        .map(|c| (c.start_line.get(), c.end_line.get(), c.copyright.clone()))
         .collect();
     let mut seen_holders: HashSet<(usize, usize, String)> = holders
         .iter()
-        .map(|h| (h.start_line, h.end_line, h.holder.clone()))
+        .map(|h| (h.start_line.get(), h.end_line.get(), h.holder.clone()))
         .collect();
 
     let mut saw_pudn_footer = false;
@@ -8553,7 +8594,7 @@ fn normalize_pudn_html_footer_copyrights(
         let expected_copyright = normalize_whitespace(&format!("(c) {years} pudn.com"));
         let expected_holder = "pudn.com".to_string();
 
-        let ckey = (ln, ln, expected_copyright.clone());
+        let ckey = (ln.get(), ln.get(), expected_copyright.clone());
         if seen_copyrights.insert(ckey) {
             copyrights.push(CopyrightDetection {
                 copyright: expected_copyright.clone(),
@@ -8562,7 +8603,7 @@ fn normalize_pudn_html_footer_copyrights(
             });
         }
 
-        let hkey = (ln, ln, expected_holder.clone());
+        let hkey = (ln.get(), ln.get(), expected_holder.clone());
         if seen_holders.insert(hkey) {
             holders.push(HolderDetection {
                 holder: expected_holder,
@@ -8683,8 +8724,8 @@ fn fallback_year_only_copyrights(groups: &[Vec<(usize, String)>]) -> Vec<Copyrig
                     {
                         out.push(CopyrightDetection {
                             copyright: refined,
-                            start_line: *ln,
-                            end_line: *ln,
+                            start_line: LineNumber::new(*ln).expect("invalid line number"),
+                            end_line: LineNumber::new(*ln).expect("invalid line number"),
                         });
                     }
                 }
@@ -8697,8 +8738,8 @@ fn fallback_year_only_copyrights(groups: &[Vec<(usize, String)>]) -> Vec<Copyrig
             {
                 out.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -8708,8 +8749,8 @@ fn fallback_year_only_copyrights(groups: &[Vec<(usize, String)>]) -> Vec<Copyrig
             {
                 out.push(CopyrightDetection {
                     copyright: refined,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -8766,8 +8807,8 @@ fn extract_copyright_c_year_comma_name_angle_email_lines(
             if seen_copyrights.insert(cr.to_ascii_lowercase()) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -8776,8 +8817,8 @@ fn extract_copyright_c_year_comma_name_angle_email_lines(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -8829,8 +8870,8 @@ fn extend_software_in_the_public_interest_holder(
         if seen_copyrights.insert(cr.to_ascii_lowercase()) {
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line: *ln,
-                end_line: *ln,
+                start_line: LineNumber::new(*ln).expect("invalid line number"),
+                end_line: LineNumber::new(*ln).expect("invalid line number"),
             });
         }
 
@@ -8841,8 +8882,8 @@ fn extend_software_in_the_public_interest_holder(
         if !holders.iter().any(|h| h.holder == holder_raw) {
             holders.push(HolderDetection {
                 holder: holder_raw.to_string(),
-                start_line: *ln,
-                end_line: *ln,
+                start_line: LineNumber::new(*ln).expect("invalid line number"),
+                end_line: LineNumber::new(*ln).expect("invalid line number"),
             });
         }
     }
@@ -8944,8 +8985,8 @@ fn extract_name_before_rewrited_by_copyrights(
         {
             copyrights.push(CopyrightDetection {
                 copyright: refined,
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
 
@@ -8955,8 +8996,8 @@ fn extract_name_before_rewrited_by_copyrights(
         {
             holders.push(HolderDetection {
                 holder,
-                start_line: ln1,
-                end_line: ln2,
+                start_line: LineNumber::new(ln1).expect("valid"),
+                end_line: LineNumber::new(ln2).expect("valid"),
             });
         }
     }
@@ -9005,16 +9046,16 @@ fn extract_developed_at_software_copyrights(
                 if seen_copyrights.insert(cr.clone()) {
                     copyrights.push(CopyrightDetection {
                         copyright: cr,
-                        start_line: ln,
-                        end_line: ln,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln).unwrap(),
                     });
                 }
                 let h = holder.to_string();
                 if seen_holders.insert(h.clone()) {
                     holders.push(HolderDetection {
                         holder: h,
-                        start_line: ln,
-                        end_line: ln,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln).unwrap(),
                     });
                 }
             }
@@ -9082,8 +9123,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     copyrights.push(CopyrightDetection {
                         copyright: refined,
-                        start_line: ln,
-                        end_line: ln,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln).unwrap(),
                     });
                 }
                 if let Some(h) = refine_holder_in_copyright_context(holder)
@@ -9091,8 +9132,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     holders.push(HolderDetection {
                         holder: h,
-                        start_line: ln,
-                        end_line: ln,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln).unwrap(),
                     });
                 }
 
@@ -9123,8 +9164,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     copyrights.push(CopyrightDetection {
                         copyright: cr,
-                        start_line: ln,
-                        end_line: ln + 1,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln + 1).expect("invalid line number"),
                     });
                 }
                 let holder_raw = format!("{tag} {next_clean}");
@@ -9133,8 +9174,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     holders.push(HolderDetection {
                         holder: h,
-                        start_line: ln,
-                        end_line: ln + 1,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln + 1).expect("invalid line number"),
                     });
                 }
             }
@@ -9160,8 +9201,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     copyrights.push(CopyrightDetection {
                         copyright: cr,
-                        start_line: ln,
-                        end_line: ln + 1,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln + 1).expect("invalid line number"),
                     });
                 }
 
@@ -9176,8 +9217,8 @@ fn extract_confidential_proprietary_copyrights(
                 {
                     holders.push(HolderDetection {
                         holder: h,
-                        start_line: ln,
-                        end_line: ln + 1,
+                        start_line: LineNumber::new(ln).unwrap(),
+                        end_line: LineNumber::new(ln + 1).expect("invalid line number"),
                     });
                 }
             }
@@ -9275,8 +9316,8 @@ fn extract_copyright_year_c_holder_mid_sentence_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9285,8 +9326,8 @@ fn extract_copyright_year_c_holder_mid_sentence_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9336,8 +9377,8 @@ fn extract_javadoc_author_copyright_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9346,8 +9387,8 @@ fn extract_javadoc_author_copyright_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9380,7 +9421,7 @@ fn extract_xml_copyright_tag_c_lines(
         let ln = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.start()))
-            .unwrap_or(1);
+            .unwrap_or(LineNumber::ONE);
         let inner = cap.name("body").map(|m| m.as_str()).unwrap_or("");
         if inner.is_empty() {
             continue;
@@ -9488,8 +9529,8 @@ fn extract_copyright_its_authors_lines(
             if seen_copyrights.insert(cr.clone()) {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9497,8 +9538,8 @@ fn extract_copyright_its_authors_lines(
             if seen_holders.insert(holder.clone()) {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9539,8 +9580,8 @@ fn extract_us_government_year_placeholder_copyrights(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9550,8 +9591,8 @@ fn extract_us_government_year_placeholder_copyrights(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9595,8 +9636,8 @@ fn extract_copyright_notice_paren_year_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9605,8 +9646,8 @@ fn extract_copyright_notice_paren_year_lines(
             {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9702,7 +9743,7 @@ fn extract_html_anchor_copyright_url(
         let start_line = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.start()))
-            .unwrap_or(1);
+            .unwrap_or(LineNumber::ONE);
         let end_line = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.end()))
@@ -9773,16 +9814,15 @@ fn extract_angle_bracket_year_name_copyrights(
             let full_lower = full.to_ascii_lowercase();
             if !seen_copyrights.contains(&full_lower) {
                 let short = format!("Copyright (c) <{years}>");
-                if let Some(existing) = copyrights
-                    .iter_mut()
-                    .find(|c| c.start_line == *ln && c.end_line == *ln && c.copyright == short)
-                {
+                if let Some(existing) = copyrights.iter_mut().find(|c| {
+                    c.start_line.get() == *ln && c.end_line.get() == *ln && c.copyright == short
+                }) {
                     existing.copyright = full.clone();
                 } else {
                     copyrights.push(CopyrightDetection {
                         copyright: full.clone(),
-                        start_line: *ln,
-                        end_line: *ln,
+                        start_line: LineNumber::new(*ln).expect("invalid line number"),
+                        end_line: LineNumber::new(*ln).expect("invalid line number"),
                     });
                 }
                 seen_copyrights.insert(full_lower);
@@ -9794,8 +9834,8 @@ fn extract_angle_bracket_year_name_copyrights(
             if seen_holders.insert(holder_lower) {
                 holders.push(HolderDetection {
                     holder,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -9840,7 +9880,7 @@ fn extract_html_icon_class_copyrights(
         let ln = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.start()))
-            .unwrap_or(1);
+            .unwrap_or(LineNumber::ONE);
         let year = cap.name("year").map(|m| m.as_str()).unwrap_or("").trim();
         if year.is_empty() {
             continue;
@@ -9871,7 +9911,7 @@ fn extract_html_icon_class_copyrights(
         let ln = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.start()))
-            .unwrap_or(1);
+            .unwrap_or(LineNumber::ONE);
         let url = cap.name("url").map(|m| m.as_str()).unwrap_or("").trim();
         if url.is_empty() {
             continue;
@@ -9906,7 +9946,7 @@ fn extract_html_icon_class_copyrights(
         let ln = cap
             .get(0)
             .map(|m| line_number_index.line_number_at_offset(m.start()))
-            .unwrap_or(1);
+            .unwrap_or(LineNumber::ONE);
         let years = cap.name("years").map(|m| m.as_str()).unwrap_or("").trim();
         if years.is_empty() {
             continue;
@@ -9973,8 +10013,8 @@ fn extract_copyright_year_c_name_angle_email_lines(
             {
                 copyrights.push(CopyrightDetection {
                     copyright: cr,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
 
@@ -9983,8 +10023,8 @@ fn extract_copyright_year_c_name_angle_email_lines(
             {
                 holders.push(HolderDetection {
                     holder: h,
-                    start_line: *ln,
-                    end_line: *ln,
+                    start_line: LineNumber::new(*ln).expect("invalid line number"),
+                    end_line: LineNumber::new(*ln).expect("invalid line number"),
                 });
             }
         }
@@ -10039,8 +10079,8 @@ fn extract_copyright_by_without_year_lines(
             let end_line = group.last().map(|(n, _)| *n).unwrap_or(start_line);
             copyrights.push(CopyrightDetection {
                 copyright: cr,
-                start_line,
-                end_line,
+                start_line: LineNumber::new(start_line).expect("valid"),
+                end_line: LineNumber::new(end_line).expect("valid"),
             });
         }
 
@@ -10051,8 +10091,8 @@ fn extract_copyright_by_without_year_lines(
             let end_line = group.last().map(|(n, _)| *n).unwrap_or(start_line);
             holders.push(HolderDetection {
                 holder,
-                start_line,
-                end_line,
+                start_line: LineNumber::new(start_line).expect("valid"),
+                end_line: LineNumber::new(end_line).expect("valid"),
             });
         }
     }
@@ -10067,13 +10107,13 @@ fn drop_shadowed_and_or_holders(holders: &mut Vec<HolderDetection>) {
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .push(h.holder.clone());
     }
 
     holders.retain(|h| {
-        let Some(group) = by_span.get(&(h.start_line, h.end_line)) else {
+        let Some(group) = by_span.get(&(h.start_line.get(), h.end_line.get())) else {
             return true;
         };
 
@@ -10101,13 +10141,13 @@ fn drop_shadowed_prefix_holders(holders: &mut Vec<HolderDetection>) {
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for h in holders.iter() {
         by_span
-            .entry((h.start_line, h.end_line))
+            .entry((h.start_line.get(), h.end_line.get()))
             .or_default()
             .push(h.holder.clone());
     }
 
     holders.retain(|h| {
-        let Some(group) = by_span.get(&(h.start_line, h.end_line)) else {
+        let Some(group) = by_span.get(&(h.start_line.get(), h.end_line.get())) else {
             return true;
         };
 
@@ -10175,13 +10215,13 @@ fn drop_shadowed_prefix_copyrights(copyrights: &mut Vec<CopyrightDetection>) {
     let mut by_span: HashMap<(usize, usize), Vec<String>> = HashMap::new();
     for c in copyrights.iter() {
         by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .push(c.copyright.clone());
     }
 
     copyrights.retain(|c| {
-        let Some(group) = by_span.get(&(c.start_line, c.end_line)) else {
+        let Some(group) = by_span.get(&(c.start_line.get(), c.end_line.get())) else {
             return true;
         };
         let short = c.copyright.as_str();
@@ -10287,7 +10327,7 @@ fn drop_shadowed_bare_c_copyrights_same_span(copyrights: &mut Vec<CopyrightDetec
             continue;
         }
         bare_by_span
-            .entry((c.start_line, c.end_line))
+            .entry((c.start_line.get(), c.end_line.get()))
             .or_default()
             .insert(normalize_whitespace(tail));
     }
@@ -10302,7 +10342,7 @@ fn drop_shadowed_bare_c_copyrights_same_span(copyrights: &mut Vec<CopyrightDetec
             return true;
         }
         bare_by_span
-            .get(&(c.start_line, c.end_line))
+            .get(&(c.start_line.get(), c.end_line.get()))
             .is_none_or(|set| !set.contains(&trimmed))
     });
 }
@@ -10330,7 +10370,11 @@ fn drop_copyright_shadowed_by_bare_c_copyrights_same_span(
         {
             continue;
         }
-        tails.insert((c.start_line, c.end_line, normalize_whitespace(tail)));
+        tails.insert((
+            c.start_line.get(),
+            c.end_line.get(),
+            normalize_whitespace(tail),
+        ));
     }
 
     if tails.is_empty() {
@@ -10345,7 +10389,7 @@ fn drop_copyright_shadowed_by_bare_c_copyrights_same_span(
         {
             return true;
         }
-        !tails.contains(&(c.start_line, c.end_line, trimmed))
+        !tails.contains(&(c.start_line.get(), c.end_line.get(), trimmed))
     });
 }
 
@@ -10365,8 +10409,8 @@ fn drop_shadowed_copyright_c_years_only_prefixes(copyrights: &mut Vec<CopyrightD
         .iter()
         .map(|c| {
             (
-                c.start_line,
-                c.end_line,
+                c.start_line.get(),
+                c.end_line.get(),
                 normalize_whitespace(c.copyright.trim()),
             )
         })
@@ -10400,8 +10444,8 @@ fn drop_shadowed_copyright_c_years_only_prefixes(copyrights: &mut Vec<CopyrightD
 
     copyrights.retain(|c| {
         let key = (
-            c.start_line,
-            c.end_line,
+            c.start_line.get(),
+            c.end_line.get(),
             normalize_whitespace(c.copyright.trim()),
         );
         !shadowed.contains(&key)
@@ -10440,7 +10484,7 @@ fn drop_bare_c_shadowed_by_non_copyright_prefixes(copyrights: &mut Vec<Copyright
         .map(|c| {
             let norm = normalize_whitespace(c.copyright.trim());
             let lower = norm.to_ascii_lowercase();
-            (c.start_line, c.end_line, norm, lower)
+            (c.start_line.get(), c.end_line.get(), norm, lower)
         })
         .collect();
 
@@ -10452,7 +10496,7 @@ fn drop_bare_c_shadowed_by_non_copyright_prefixes(copyrights: &mut Vec<Copyright
         }
 
         for (sln, eln, other, other_lower) in &normalized {
-            if *sln != c.start_line || *eln != c.end_line {
+            if *sln != c.start_line.get() || *eln != c.end_line.get() {
                 continue;
             }
             if other_lower.starts_with("copyright") || other_lower.starts_with("(c)") {
@@ -11128,7 +11172,7 @@ fn extract_from_tree_nodes(
                 let mut node_holder_leaves = strip_all_rights_reserved(node_holder_leaves);
                 if let Some(copy_line) = copy_line {
                     node_holder_leaves.retain(|t| {
-                        t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line)
+                        t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line.get())
                     });
                 }
                 strip_trailing_commas(&mut node_holder_leaves);
@@ -11173,7 +11217,8 @@ fn extract_from_tree_nodes(
                     let mut node_holder_mini = strip_all_rights_reserved(node_holder_mini);
                     if let Some(copy_line) = copy_line {
                         node_holder_mini.retain(|t| {
-                            t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line)
+                            t.start_line >= copy_line
+                                || keep_prefix_lines.contains(&t.start_line.get())
                         });
                     }
                     strip_trailing_commas(&mut node_holder_mini);
@@ -11326,7 +11371,10 @@ fn merge_copyright_with_following_author<'a>(
     }
 
     let cr_leaves_all = collect_all_leaves(copyright_node);
-    let cr_last_line = cr_leaves_all.last().map(|t| t.start_line).unwrap_or(0);
+    let cr_last_line = cr_leaves_all
+        .last()
+        .map(|t| t.start_line)
+        .unwrap_or(LineNumber::ONE);
     let author_first_line = auth_token.start_line;
     if author_first_line != cr_last_line + 1 {
         return None;
@@ -11391,7 +11439,7 @@ fn merge_copyright_with_following_author<'a>(
 
 fn extract_sectioned_authors_from_author_node(node: &ParseNode) -> Option<Vec<AuthorDetection>> {
     let all_leaves = collect_all_leaves(node);
-    let mut header_lines: Vec<usize> = Vec::new();
+    let mut header_lines: Vec<LineNumber> = Vec::new();
     for t in &all_leaves {
         let v = t
             .value
@@ -11660,7 +11708,7 @@ fn is_name_continuation(node: &ParseNode) -> bool {
     }
 }
 
-fn is_same_line_holder_suffix_prefix(tree: &[ParseNode], idx: usize, line: usize) -> bool {
+fn is_same_line_holder_suffix_prefix(tree: &[ParseNode], idx: usize, line: LineNumber) -> bool {
     let Some(node) = tree.get(idx) else {
         return false;
     };
@@ -12256,7 +12304,7 @@ fn collect_trailing_orphan_tokens<'a>(
 fn collect_following_copyright_clause_tokens(
     tree: &[ParseNode],
     start: usize,
-    line: usize,
+    line: LineNumber,
 ) -> (Vec<&Token>, usize) {
     if start >= tree.len() {
         return (Vec::new(), 0);
@@ -12447,7 +12495,7 @@ const AUTHOR_BY_KEYWORDS: &[&str] = &[
     "patches",
 ];
 
-fn is_line_initial_keyword(tree: &[ParseNode], idx: usize, keyword_line: usize) -> bool {
+fn is_line_initial_keyword(tree: &[ParseNode], idx: usize, keyword_line: LineNumber) -> bool {
     if idx == 0 {
         return true;
     }
@@ -12930,7 +12978,7 @@ fn extract_bare_copyrights(
     copyrights: &mut Vec<CopyrightDetection>,
     holders: &mut Vec<HolderDetection>,
 ) {
-    fn has_line_start_copyright_prefix(tree: &[ParseNode], idx: usize, line: usize) -> bool {
+    fn has_line_start_copyright_prefix(tree: &[ParseNode], idx: usize, line: LineNumber) -> bool {
         let mut found_copyright = false;
         for j in (0..idx).rev() {
             for t in collect_all_leaves(&tree[j]).iter().rev() {
@@ -13667,9 +13715,9 @@ fn apply_written_by_for_markers(
 
     for cr in copyrights.iter_mut() {
         let next_line = cr.end_line.saturating_add(1);
-        let next_text = group
-            .iter()
-            .find_map(|(ln, text)| (*ln == next_line).then_some(text.as_str()));
+        let next_text = group.iter().find_map(|(ln, text)| {
+            (LineNumber::new(*ln) == Some(next_line)).then_some(text.as_str())
+        });
 
         let Some(next_text) = next_text else {
             continue;
@@ -13682,7 +13730,10 @@ fn apply_written_by_for_markers(
             cr.copyright = format!("{} Written", cr.copyright.trim_end());
         }
 
-        for h in holders.iter_mut().filter(|h| h.end_line == cr.end_line) {
+        for h in holders
+            .iter_mut()
+            .filter(|h| h.end_line.get() == cr.end_line.get())
+        {
             if !h.holder.ends_with("Written") {
                 h.holder = format!("{} Written", h.holder.trim_end());
             }
@@ -13711,8 +13762,8 @@ fn restore_bare_holder_angle_emails(
         }
 
         for cr in copyrights.iter().filter(|c| {
-            h.start_line >= c.start_line
-                && h.end_line <= c.end_line
+            h.start_line.get() >= c.start_line.get()
+                && h.end_line.get() <= c.end_line.get()
                 && !c.copyright.to_ascii_lowercase().contains("copyright")
         }) {
             let Some(cap) = LEADING_NAME_EMAIL_RE.captures(cr.copyright.as_str()) else {
@@ -13765,7 +13816,9 @@ fn build_holder_from_copyright_node(
     let leaves = collect_holder_filtered_leaves(node, ignored_labels, ignored_pos_tags);
     let mut filtered = strip_all_rights_reserved(leaves);
     if let Some(copy_line) = copy_line {
-        filtered.retain(|t| t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line));
+        filtered.retain(|t| {
+            t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line.get())
+        });
     }
 
     let allow_single_word_contributors = collect_all_leaves(node)
@@ -13775,13 +13828,13 @@ fn build_holder_from_copyright_node(
     build_holder_from_tokens(&filtered, allow_single_word_contributors)
 }
 
-fn signal_lines_before_copy_line(node: &ParseNode, copy_line: usize) -> HashSet<usize> {
+fn signal_lines_before_copy_line(node: &ParseNode, copy_line: LineNumber) -> HashSet<usize> {
     use std::collections::HashMap;
 
     let mut by_line: HashMap<usize, Vec<&Token>> = HashMap::new();
     for t in collect_all_leaves(node) {
         if t.start_line < copy_line {
-            by_line.entry(t.start_line).or_default().push(t);
+            by_line.entry(t.start_line.get()).or_default().push(t);
         }
     }
 
@@ -13867,8 +13920,14 @@ fn build_copyright_from_tokens(tokens: &[&Token]) -> Option<CopyrightDetection>
     }
     Some(CopyrightDetection {
         copyright: refined,
-        start_line: tokens.first().map(|t| t.start_line).unwrap_or(0),
-        end_line: tokens.last().map(|t| t.start_line).unwrap_or(0),
+        start_line: tokens
+            .first()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
+        end_line: tokens
+            .last()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
     })
 }
 
@@ -13890,8 +13949,14 @@ fn build_holder_from_tokens(
     }
     Some(HolderDetection {
         holder: refined,
-        start_line: tokens.first().map(|t| t.start_line).unwrap_or(0),
-        end_line: tokens.last().map(|t| t.start_line).unwrap_or(0),
+        start_line: tokens
+            .first()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
+        end_line: tokens
+            .last()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
     })
 }
 
@@ -13906,8 +13971,14 @@ fn build_author_from_tokens(tokens: &[&Token]) -> Option<AuthorDetection> {
     }
     Some(AuthorDetection {
         author: refined,
-        start_line: tokens.first().map(|t| t.start_line).unwrap_or(0),
-        end_line: tokens.last().map(|t| t.start_line).unwrap_or(0),
+        start_line: tokens
+            .first()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
+        end_line: tokens
+            .last()
+            .map(|t| t.start_line)
+            .unwrap_or(LineNumber::ONE),
     })
 }
 
@@ -14025,23 +14096,23 @@ fn drop_scan_only_holders_from_copyright_scan_lines(
 
     let copyright_spans: HashSet<(usize, usize)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line))
+        .map(|c| (c.start_line.get(), c.end_line.get()))
         .collect();
 
     holders.retain(|holder| {
-        let span = (holder.start_line, holder.end_line);
+        let span = (holder.start_line.get(), holder.end_line.get());
         if copyright_spans.contains(&span) {
             return true;
         }
         if !holder.holder.eq_ignore_ascii_case("scan") {
             return true;
         }
-        if holder.start_line == 0 || holder.start_line != holder.end_line {
+        if holder.start_line.get() != holder.end_line.get() {
             return true;
         }
 
         raw_lines
-            .get(holder.start_line - 1)
+            .get(holder.start_line.get() - 1)
             .is_none_or(|line| !COPYRIGHT_SCAN_RE.is_match(line))
     });
 }
@@ -14073,15 +14144,15 @@ fn drop_path_fragment_holders_from_bare_c_code_lines(
 
     let copyright_spans: HashSet<(usize, usize)> = copyrights
         .iter()
-        .map(|c| (c.start_line, c.end_line))
+        .map(|c| (c.start_line.get(), c.end_line.get()))
         .collect();
 
     holders.retain(|holder| {
-        let span = (holder.start_line, holder.end_line);
+        let span = (holder.start_line.get(), holder.end_line.get());
         if copyright_spans.contains(&span) {
             return true;
         }
-        if holder.start_line == 0 || holder.start_line != holder.end_line {
+        if holder.start_line.get() != holder.end_line.get() {
             return true;
         }
         if !is_path_like_code_fragment(&holder.holder) {
@@ -14089,7 +14160,7 @@ fn drop_path_fragment_holders_from_bare_c_code_lines(
         }
 
         raw_lines
-            .get(holder.start_line - 1)
+            .get(holder.start_line.get() - 1)
             .is_none_or(|line| !BARE_C_PATH_FRAGMENT_RE.is_match(line))
     });
 }
@@ -14107,7 +14178,7 @@ const YEAR_LIKE_LABELS: &[TreeLabel] = &[TreeLabel::YrRange, TreeLabel::YrAnd];
 struct HolderLeafFilterState<'a> {
     result: Vec<&'a Token>,
     last_was_year_filtered: bool,
-    last_filtered_email_or_url_line: Option<usize>,
+    last_filtered_email_or_url_line: Option<LineNumber>,
     last_filtered_email_was_angle_bracket: bool,
     pending_comma_after_filtered_email_or_url: Option<&'a Token>,
     last_filtered_was_paren_url: bool,
@@ -14247,7 +14318,7 @@ fn filter_holder_tokens_with_state<'a>(
 ) -> Vec<&'a Token> {
     let mut result = Vec::new();
     let mut last_was_year_filtered = predecessor_was_year_filtered;
-    let mut last_filtered_email_or_url_line: Option<usize> = None;
+    let mut last_filtered_email_or_url_line: Option<LineNumber> = None;
     let mut last_filtered_email_was_angle_bracket = false;
     // Track when the last filtered token was a parenthesized URL (Markdown-style
     // [Name](URL),) so we can drop the immediately following comma unconditionally.
diff --git a/src/copyright/detector_author_heuristics.rs b/src/copyright/detector_author_heuristics.rs
index 8e73f563d..6edb329fd 100644
--- a/src/copyright/detector_author_heuristics.rs
+++ b/src/copyright/detector_author_heuristics.rs
@@ -8,9 +8,10 @@ use crate::copyright::line_tracking::PreparedLineCache;
 use crate::copyright::prepare::prepare_text_line;
 use crate::copyright::refiner::refine_author;
 use crate::copyright::types::{AuthorDetection, CopyrightDetection, HolderDetection};
+use crate::models::LineNumber;
 
-fn line_number_for_offset(content: &str, offset: usize) -> usize {
-    content[..offset].bytes().filter(|b| *b == b'\n').count() + 1
+fn line_number_for_offset(content: &str, offset: usize) -> LineNumber {
+    LineNumber::from_0_indexed(content[..offset].bytes().filter(|b| *b == b'\n').count())
 }
 
 fn decode_markup_entities(value: &str) -> String {
@@ -214,8 +215,8 @@ pub(super) fn extract_multiline_written_by_author_blocks(
             {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -314,11 +315,11 @@ pub(super) fn extract_multiline_written_by_author_blocks(
             if let Some(combined) = refine_author(combined_candidate)
                 && seen.insert(combined.clone())
             {
-                authors.retain(|a| a.start_line < start_line || a.end_line > end_line);
+                authors.retain(|a| a.start_line.get() < start_line || a.end_line.get() > end_line);
                 authors.push(AuthorDetection {
                     author: combined,
-                    start_line,
-                    end_line,
+                    start_line: LineNumber::new(start_line).expect("valid"),
+                    end_line: LineNumber::new(end_line).expect("valid"),
                 });
                 i = j;
                 continue;
@@ -341,8 +342,8 @@ pub(super) fn extract_multiline_written_by_author_blocks(
                         {
                             authors.push(AuthorDetection {
                                 author,
-                                start_line,
-                                end_line,
+                                start_line: LineNumber::new(start_line).expect("valid"),
+                                end_line: LineNumber::new(end_line).expect("valid"),
                             });
                         }
                         extracted_any = true;
@@ -368,11 +369,11 @@ pub(super) fn extract_multiline_written_by_author_blocks(
             if let Some(combined) = refine_author(combined_candidate)
                 && seen.insert(combined.clone())
             {
-                authors.retain(|a| a.start_line < start_line || a.end_line > end_line);
+                authors.retain(|a| a.start_line.get() < start_line || a.end_line.get() > end_line);
                 authors.push(AuthorDetection {
                     author: combined,
-                    start_line,
-                    end_line,
+                    start_line: LineNumber::new(start_line).expect("valid"),
+                    end_line: LineNumber::new(end_line).expect("valid"),
                 });
             }
         }
@@ -413,8 +414,8 @@ pub(super) fn extract_json_excerpt_developed_by_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
             });
         }
     }
@@ -504,8 +505,8 @@ pub(super) fn extract_module_author_macros(
             if seen.insert(author.clone()) {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -604,8 +605,8 @@ pub(super) fn extract_was_developed_by_author_blocks(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: end_ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(end_ln).expect("invalid line number"),
             });
         }
 
@@ -781,11 +782,11 @@ pub(super) fn extract_author_colon_blocks(
         };
 
         if seen.insert(combined.clone()) {
-            authors.retain(|a| a.start_line < start_line || a.end_line > end_line);
+            authors.retain(|a| a.start_line.get() < start_line || a.end_line.get() > end_line);
             authors.push(AuthorDetection {
                 author: combined,
-                start_line,
-                end_line,
+                start_line: LineNumber::new(start_line).expect("valid"),
+                end_line: LineNumber::new(end_line).expect("valid"),
             });
         }
 
@@ -944,8 +945,8 @@ pub(super) fn extract_code_written_by_author_blocks(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: j,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(j).expect("invalid line number"),
             });
         }
 
@@ -1024,8 +1025,8 @@ pub(super) fn extract_developed_and_created_by_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author: author.clone(),
-                start_line: start_idx + 1,
-                end_line: end_idx + 1,
+                start_line: LineNumber::from_0_indexed(start_idx),
+                end_line: LineNumber::from_0_indexed(end_idx),
             });
         }
 
@@ -1064,8 +1065,8 @@ pub(super) fn extract_with_additional_hacking_by_authors(
         {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
@@ -1139,17 +1140,20 @@ pub(super) fn merge_metadata_author_and_email_lines(
             if seen.insert(combined.clone()) {
                 authors.push(AuthorDetection {
                     author: combined,
-                    start_line: author_ln,
-                    end_line: email_ln,
+                    start_line: LineNumber::new(author_ln).expect("invalid line number"),
+                    end_line: LineNumber::new(email_ln).expect("invalid line number"),
                 });
             }
 
             authors.retain(|a| {
-                if a.start_line == author_ln && a.end_line == author_ln && a.author == name {
+                if a.start_line.get() == author_ln
+                    && a.end_line.get() == author_ln
+                    && a.author == name
+                {
                     return false;
                 }
-                if a.start_line == email_ln
-                    && a.end_line == email_ln
+                if a.start_line.get() == email_ln
+                    && a.end_line.get() == email_ln
                     && a.author.to_ascii_lowercase() == format!("author-email {email}")
                 {
                     return false;
@@ -1217,8 +1221,8 @@ pub(super) fn extract_debian_maintainer_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
@@ -1247,8 +1251,8 @@ pub(super) fn extract_created_by_project_author(
             if seen.insert(author.clone()) {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
             break;
@@ -1300,8 +1304,8 @@ pub(super) fn extract_created_by_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author: author.clone(),
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
 
@@ -1344,11 +1348,11 @@ pub(super) fn extract_written_by_comma_and_copyright_authors(
             continue;
         };
         if seen.insert(author.clone()) {
-            authors.retain(|a| !(a.start_line == ln && a.end_line == ln));
+            authors.retain(|a| !(a.start_line.get() == ln && a.end_line.get() == ln));
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
@@ -1403,8 +1407,8 @@ pub(super) fn extract_package_comment_named_authors(
             {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -1465,8 +1469,8 @@ pub(super) fn extract_developed_by_sentence_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
@@ -1514,8 +1518,8 @@ pub(super) fn extract_developed_by_phrase_authors(
             if seen.insert(author.clone()) {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -1559,8 +1563,8 @@ pub(super) fn extract_maintained_by_authors(
             if seen.insert(author.clone()) {
                 authors.push(AuthorDetection {
                     author,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -1623,8 +1627,8 @@ pub(super) fn extract_converted_to_by_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author: author.clone(),
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
         if add_converted_variant {
@@ -1632,8 +1636,8 @@ pub(super) fn extract_converted_to_by_authors(
             if seen.insert(converted.clone()) {
                 authors.push(AuthorDetection {
                     author: converted,
-                    start_line: ln,
-                    end_line: ln,
+                    start_line: LineNumber::new(ln).expect("invalid line number"),
+                    end_line: LineNumber::new(ln).expect("invalid line number"),
                 });
             }
         }
@@ -1679,8 +1683,8 @@ pub(super) fn extract_various_bugfixes_and_enhancements_by_authors(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
@@ -1791,10 +1795,12 @@ pub(super) fn drop_ref_markup_authors(authors: &mut Vec<AuthorDetection>) {
 
 pub(super) fn normalize_json_blob_authors(raw_lines: &[&str], authors: &mut Vec<AuthorDetection>) {
     let mut normalized: Vec<AuthorDetection> = Vec::with_capacity(authors.len());
-    let mut seen: HashSet<(usize, usize, String)> = HashSet::new();
+    let mut seen: HashSet<(LineNumber, LineNumber, String)> = HashSet::new();
 
     for author in authors.iter() {
-        let Some(window) = json_author_window(raw_lines, author.start_line, author.end_line) else {
+        let Some(window) =
+            json_author_window(raw_lines, author.start_line.get(), author.end_line.get())
+        else {
             let key = (author.start_line, author.end_line, author.author.clone());
             if seen.insert(key) {
                 normalized.push(author.clone());
@@ -2023,8 +2029,8 @@ pub(super) fn extract_dense_name_email_author_lists(
         if seen.insert(author.clone()) {
             authors.push(AuthorDetection {
                 author,
-                start_line: ln,
-                end_line: ln,
+                start_line: LineNumber::new(ln).expect("invalid line number"),
+                end_line: LineNumber::new(ln).expect("invalid line number"),
             });
         }
     }
diff --git a/src/copyright/detector_test.rs b/src/copyright/detector_test.rs
index 44a414623..8a7c38f2a 100644
--- a/src/copyright/detector_test.rs
+++ b/src/copyright/detector_test.rs
@@ -1,4 +1,5 @@
 use super::*;
+use crate::models::LineNumber;
 use std::fs;
 use std::path::PathBuf;
 
@@ -20,13 +21,13 @@ fn test_drop_shadowed_year_only_prefix_same_start_line() {
     let mut copyrights = vec![
         CopyrightDetection {
             copyright: "(c) 2001".to_string(),
-            start_line: 5,
-            end_line: 5,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(5).unwrap(),
         },
         CopyrightDetection {
             copyright: "(c) 2001 Foo Bar".to_string(),
-            start_line: 5,
-            end_line: 5,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(5).unwrap(),
         },
     ];
     drop_shadowed_year_only_copyright_prefixes_same_start_line(&mut copyrights);
@@ -735,7 +736,7 @@ fn test_extract_from_tree_nodes_builds_hall_holder_tokens() {
     let mut debug_lines: Vec<String> = Vec::new();
     for (i, node) in tree.iter().enumerate() {
         let leaves = collect_all_leaves(node);
-        let line = leaves.first().map(|t| t.start_line).unwrap_or(0);
+        let line = leaves.first().map(|t| t.start_line.get()).unwrap_or(0);
         let has_2004 = leaves
             .iter()
             .any(|t| t.tag == PosTag::Yr && t.value.starts_with("2004"));
@@ -777,10 +778,10 @@ fn test_extract_from_tree_nodes_builds_hall_holder_tokens() {
     let copy_line = collect_all_leaves(hall_node)
         .iter()
         .filter(|t| t.tag == PosTag::Copy && t.value.eq_ignore_ascii_case("copyright"))
-        .map(|t| t.start_line)
+        .map(|t| t.start_line.get())
         .min();
     let keep_prefix_lines = copy_line
-        .map(|cl| signal_lines_before_copy_line(hall_node, cl))
+        .map(|cl| signal_lines_before_copy_line(hall_node, LineNumber::new(cl).unwrap()))
         .unwrap_or_default();
 
     let node_holder_leaves =
@@ -788,8 +789,9 @@ fn test_extract_from_tree_nodes_builds_hall_holder_tokens() {
     let mut holder_tokens: Vec<&Token> = Vec::new();
     let mut node_holder_leaves = strip_all_rights_reserved(node_holder_leaves);
     if let Some(copy_line) = copy_line {
-        node_holder_leaves
-            .retain(|t| t.start_line >= copy_line || keep_prefix_lines.contains(&t.start_line));
+        node_holder_leaves.retain(|t| {
+            t.start_line.get() >= copy_line || keep_prefix_lines.contains(&t.start_line.get())
+        });
     }
     holder_tokens.extend(node_holder_leaves);
     holder_tokens.extend(&trailing_tokens);
@@ -2034,7 +2036,7 @@ fn test_detect_simple_copyright() {
         "Should contain year: {}",
         c[0].copyright
     );
-    assert_eq!(c[0].start_line, 1);
+    assert_eq!(c[0].start_line, LineNumber::ONE);
     assert!(!h.is_empty(), "Should detect holder");
 }
 
@@ -2231,8 +2233,8 @@ fn test_detect_author() {
     assert!(h.is_empty(), "Should not detect holder");
     assert_eq!(a.len(), 1, "Should detect one author, got: {:?}", a);
     assert_eq!(a[0].author, "John Doe");
-    assert_eq!(a[0].start_line, 1);
-    assert_eq!(a[0].end_line, 1);
+    assert_eq!(a[0].start_line, LineNumber::ONE);
+    assert_eq!(a[0].end_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2244,8 +2246,8 @@ fn test_detect_author_from_xml_author_attribute() {
     assert!(h.is_empty(), "Should not detect holder");
     assert_eq!(a.len(), 1, "Should detect one author, got: {:?}", a);
     assert_eq!(a[0].author, "Vinnie Falco");
-    assert_eq!(a[0].start_line, 1);
-    assert_eq!(a[0].end_line, 1);
+    assert_eq!(a[0].start_line, LineNumber::ONE);
+    assert_eq!(a[0].end_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2337,7 +2339,11 @@ fn test_detect_line_numbers() {
     let text = "Some header\nCopyright 2024 Acme Inc.\nSome footer";
     let (c, _h, _a) = detect_copyrights_from_text(text);
     assert!(!c.is_empty(), "Should detect copyright");
-    assert_eq!(c[0].start_line, 2, "Copyright should be on line 2");
+    assert_eq!(
+        c[0].start_line,
+        LineNumber::new(2).unwrap(),
+        "Copyright should be on line 2"
+    );
 }
 
 #[test]
@@ -2345,11 +2351,11 @@ fn test_detect_copyright_year_range() {
     let (c, h, _a) = detect_copyrights_from_text("Copyright 2020-2024 Foo Corp.");
     assert_eq!(c.len(), 1, "Should detect one copyright, got: {:?}", c);
     assert_eq!(c[0].copyright, "Copyright 2020-2024 Foo Corp.");
-    assert_eq!(c[0].start_line, 1);
-    assert_eq!(c[0].end_line, 1);
+    assert_eq!(c[0].start_line, LineNumber::ONE);
+    assert_eq!(c[0].end_line, LineNumber::ONE);
     assert_eq!(h.len(), 1, "Should detect one holder, got: {:?}", h);
     assert_eq!(h[0].holder, "Foo Corp.");
-    assert_eq!(h[0].start_line, 1);
+    assert_eq!(h[0].start_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2710,12 +2716,12 @@ fn test_detect_copyright_and_author_same_text() {
     let (c, h, a) = detect_copyrights_from_text(text);
     assert_eq!(c.len(), 1, "Should detect one copyright, got: {:?}", c);
     assert_eq!(c[0].copyright, "Copyright 2024 Acme Inc.");
-    assert_eq!(c[0].start_line, 1);
+    assert_eq!(c[0].start_line, LineNumber::ONE);
     assert_eq!(h.len(), 1, "Should detect one holder, got: {:?}", h);
     assert_eq!(h[0].holder, "Acme Inc.");
     assert_eq!(a.len(), 1, "Should detect one author, got: {:?}", a);
     assert_eq!(a[0].author, "Jane Smith");
-    assert_eq!(a[0].start_line, 5);
+    assert_eq!(a[0].start_line, LineNumber::new(5).unwrap());
 }
 
 #[test]
@@ -2723,8 +2729,8 @@ fn test_detect_author_written_by() {
     let (_c, _h, a) = detect_copyrights_from_text("Written by Jane Smith");
     assert_eq!(a.len(), 1, "Should detect one author, got: {:?}", a);
     assert_eq!(a[0].author, "Jane Smith");
-    assert_eq!(a[0].start_line, 1);
-    assert_eq!(a[0].end_line, 1);
+    assert_eq!(a[0].start_line, LineNumber::ONE);
+    assert_eq!(a[0].end_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2732,8 +2738,8 @@ fn test_detect_author_maintained_by() {
     let (_c, _h, a) = detect_copyrights_from_text("Maintained by Bob Jones");
     assert_eq!(a.len(), 1, "Should detect one author, got: {:?}", a);
     assert_eq!(a[0].author, "Bob Jones");
-    assert_eq!(a[0].start_line, 1);
-    assert_eq!(a[0].end_line, 1);
+    assert_eq!(a[0].start_line, LineNumber::ONE);
+    assert_eq!(a[0].end_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2785,10 +2791,10 @@ fn test_detect_copyright_with_company() {
     let (c, h, _a) = detect_copyrights_from_text("Copyright (c) 2024 Google LLC");
     assert_eq!(c.len(), 1, "Should detect one copyright, got: {:?}", c);
     assert_eq!(c[0].copyright, "Copyright (c) 2024 Google LLC");
-    assert_eq!(c[0].start_line, 1);
+    assert_eq!(c[0].start_line, LineNumber::ONE);
     assert_eq!(h.len(), 1, "Should detect one holder, got: {:?}", h);
     assert_eq!(h[0].holder, "Google LLC");
-    assert_eq!(h[0].start_line, 1);
+    assert_eq!(h[0].start_line, LineNumber::ONE);
 }
 
 #[test]
@@ -2799,10 +2805,10 @@ fn test_detect_copyright_all_rights_reserved() {
         c[0].copyright, "Copyright 2024 Apple Inc.",
         "All rights reserved should be stripped from copyright text"
     );
-    assert_eq!(c[0].start_line, 1);
+    assert_eq!(c[0].start_line, LineNumber::ONE);
     assert_eq!(h.len(), 1, "Should detect one holder, got: {:?}", h);
     assert_eq!(h[0].holder, "Apple Inc.");
-    assert_eq!(h[0].start_line, 1);
+    assert_eq!(h[0].start_line, LineNumber::ONE);
 }
 
 // ── strip_all_rights_reserved ────────────────────────────────────
@@ -2813,32 +2819,32 @@ fn test_strip_all_rights_reserved_basic() {
         Token {
             value: "Copyright".to_string(),
             tag: PosTag::Copy,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
         Token {
             value: "2024".to_string(),
             tag: PosTag::Yr,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
         Token {
             value: "Acme".to_string(),
             tag: PosTag::Nnp,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
         Token {
             value: "All".to_string(),
             tag: PosTag::Nn,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
         Token {
             value: "Rights".to_string(),
             tag: PosTag::Right,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
         Token {
             value: "Reserved".to_string(),
             tag: PosTag::Reserved,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         },
     ];
     let refs: Vec<&Token> = tokens.iter().collect();
@@ -2859,17 +2865,17 @@ fn test_collect_filtered_leaves_filters_pos_tags() {
             ParseNode::Leaf(Token {
                 value: "Copyright".to_string(),
                 tag: PosTag::Copy,
-                start_line: 1,
+                start_line: LineNumber::ONE,
             }),
             ParseNode::Leaf(Token {
                 value: "2024".to_string(),
                 tag: PosTag::Yr,
-                start_line: 1,
+                start_line: LineNumber::ONE,
             }),
             ParseNode::Leaf(Token {
                 value: "Acme".to_string(),
                 tag: PosTag::Nnp,
-                start_line: 1,
+                start_line: LineNumber::ONE,
             }),
         ],
     };
@@ -2887,20 +2893,20 @@ fn test_collect_filtered_leaves_filters_tree_labels() {
             ParseNode::Leaf(Token {
                 value: "Copyright".to_string(),
                 tag: PosTag::Copy,
-                start_line: 1,
+                start_line: LineNumber::ONE,
             }),
             ParseNode::Tree {
                 label: TreeLabel::YrRange,
                 children: vec![ParseNode::Leaf(Token {
                     value: "2024".to_string(),
                     tag: PosTag::Yr,
-                    start_line: 1,
+                    start_line: LineNumber::ONE,
                 })],
             },
             ParseNode::Leaf(Token {
                 value: "Acme".to_string(),
                 tag: PosTag::Nnp,
-                start_line: 1,
+                start_line: LineNumber::ONE,
             }),
         ],
     };
@@ -3067,23 +3073,23 @@ fn test_drop_shadowed_c_sign_variants_unit() {
     let mut c = vec![
         CopyrightDetection {
             copyright: "Copyright 2007, 2010 Linux Foundation".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
         CopyrightDetection {
             copyright: "Copyright (c) 2007, 2010 Linux Foundation".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
         CopyrightDetection {
             copyright: "Copyright 1995-2010 Jean-loup Gailly and Mark Adler".to_string(),
-            start_line: 10,
-            end_line: 10,
+            start_line: LineNumber::new(10).unwrap(),
+            end_line: LineNumber::new(10).unwrap(),
         },
         CopyrightDetection {
             copyright: "Copyright (c) 1995-2010 Jean-loup Gailly and Mark Adler".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
     ];
     drop_shadowed_c_sign_variants(&mut c);
@@ -3405,13 +3411,21 @@ fn test_html_anchor_copyright_url_multiline_span_preserved() {
         .iter()
         .find(|cr| cr.copyright == "copyright https://example.com/path")
         .unwrap();
-    assert_eq!((cd.start_line, cd.end_line), (1, 3), "copyrights: {c:?}");
+    assert_eq!(
+        (cd.start_line, cd.end_line),
+        (LineNumber::new(1).unwrap(), LineNumber::new(3).unwrap()),
+        "copyrights: {c:?}"
+    );
 
     let hd = h
         .iter()
         .find(|hr| hr.holder == "https://example.com/path")
         .unwrap();
-    assert_eq!((hd.start_line, hd.end_line), (1, 3), "holders: {h:?}");
+    assert_eq!(
+        (hd.start_line, hd.end_line),
+        (LineNumber::new(1).unwrap(), LineNumber::new(3).unwrap()),
+        "holders: {h:?}"
+    );
 }
 
 #[test]
@@ -4135,8 +4149,8 @@ fn test_boost_style_multiline_holder_continuation_after_year_first_line() {
 
     assert!(
         copyrights.iter().any(|c| {
-            c.start_line == 1
-                && c.end_line == 2
+            c.start_line == LineNumber::ONE
+                && c.end_line == LineNumber::new(2).unwrap()
                 && c.copyright.contains("Peter Dimov")
                 && c.copyright.contains("Vinnie Falco")
         }),
@@ -4145,8 +4159,8 @@ fn test_boost_style_multiline_holder_continuation_after_year_first_line() {
 
     assert!(
         holders.iter().any(|h| {
-            h.start_line == 1
-                && h.end_line == 2
+            h.start_line == LineNumber::ONE
+                && h.end_line == LineNumber::new(2).unwrap()
                 && h.holder.contains("Peter Dimov")
                 && h.holder.contains("Vinnie Falco")
         }),
@@ -4164,8 +4178,8 @@ Jean-Luc.Richier@imag.fr, IMAG-LSR.\n";
 
     assert!(
         copyrights.iter().any(|c| {
-            c.start_line == 1
-                && c.end_line == 1
+            c.start_line == LineNumber::ONE
+                && c.end_line == LineNumber::ONE
                 && c.copyright == "Copyright (c) 1995, 1996, 1997 Francis.Dupont@inria.fr, INRIA"
         }),
         "copyrights: {copyrights:?}"
@@ -4193,7 +4207,7 @@ fn test_extend_copyright_with_following_all_rights_reserved_line() {
     assert!(
         copyrights
             .iter()
-            .any(|c| c.start_line == 1 && c.end_line == 2),
+            .any(|c| c.start_line == LineNumber::ONE && c.end_line == LineNumber::new(2).unwrap()),
         "copyrights: {copyrights:?}"
     );
     assert!(
diff --git a/src/copyright/lexer.rs b/src/copyright/lexer.rs
index 6cbf0143a..e6d1d2b9c 100644
--- a/src/copyright/lexer.rs
+++ b/src/copyright/lexer.rs
@@ -12,6 +12,7 @@ use regex::Regex;
 
 use super::patterns::COMPILED_PATTERNS;
 use super::types::{PosTag, Token};
+use crate::models::LineNumber;
 
 /// Splitter regex: splits on tabs, spaces, equals signs, and semicolons.
 /// Matches Python's `re.compile(r'[\t =;]+').split`.
@@ -47,7 +48,7 @@ pub fn get_tokens(numbered_lines: &[(usize, String)]) -> Vec<Token> {
                 tokens.push(Token {
                     value: "\n".to_string(),
                     tag: PosTag::EmptyLine,
-                    start_line: *start_line,
+                    start_line: LineNumber::new(*start_line).expect("invalid line number"),
                 });
                 last_line.clear();
                 continue;
@@ -78,12 +79,12 @@ pub fn get_tokens(numbered_lines: &[(usize, String)]) -> Vec<Token> {
                     tokens.push(Token {
                         value: base.to_string(),
                         tag,
-                        start_line: *start_line,
+                        start_line: LineNumber::new(*start_line).expect("invalid line number"),
                     });
                     tokens.push(Token {
                         value: ",".to_string(),
                         tag: PosTag::Cc,
-                        start_line: *start_line,
+                        start_line: LineNumber::new(*start_line).expect("invalid line number"),
                     });
                     continue;
                 }
@@ -94,7 +95,7 @@ pub fn get_tokens(numbered_lines: &[(usize, String)]) -> Vec<Token> {
             tokens.push(Token {
                 value: tok,
                 tag,
-                start_line: *start_line,
+                start_line: LineNumber::new(*start_line).expect("invalid line number"),
             });
         }
     }
diff --git a/src/copyright/lexer_test.rs b/src/copyright/lexer_test.rs
index 4c61e258f..e9ea62f8f 100644
--- a/src/copyright/lexer_test.rs
+++ b/src/copyright/lexer_test.rs
@@ -1,4 +1,5 @@
 use super::*;
+use crate::models::LineNumber;
 
 #[test]
 fn test_simple_copyright_line() {
@@ -8,7 +9,7 @@ fn test_simple_copyright_line() {
 
     assert_eq!(tokens[0].value, "Copyright");
     assert_eq!(tokens[0].tag, PosTag::Copy);
-    assert_eq!(tokens[0].start_line, 1);
+    assert_eq!(tokens[0].start_line, LineNumber::ONE);
 
     assert_eq!(tokens[1].value, "2024");
     assert_eq!(tokens[1].tag, PosTag::Yr);
@@ -109,10 +110,10 @@ fn test_line_numbers_preserved() {
         (11, "Acme Inc.".to_string()),
     ];
     let tokens = get_tokens(&lines);
-    assert_eq!(tokens[0].start_line, 10);
+    assert_eq!(tokens[0].start_line, LineNumber::new(10).unwrap());
     // "Acme" should be on line 11
     let acme = tokens.iter().find(|t| t.value == "Acme").unwrap();
-    assert_eq!(acme.start_line, 11);
+    assert_eq!(acme.start_line, LineNumber::new(11).unwrap());
 }
 
 #[test]
diff --git a/src/copyright/line_tracking.rs b/src/copyright/line_tracking.rs
index 34567f5d2..80fbe3e39 100644
--- a/src/copyright/line_tracking.rs
+++ b/src/copyright/line_tracking.rs
@@ -1,4 +1,5 @@
 use super::prepare::prepare_text_line;
+use crate::models::LineNumber;
 
 pub(super) struct PreparedLineCache<'a> {
     raw_lines: &'a [&'a str],
@@ -78,10 +79,11 @@ impl LineNumberIndex {
         }
     }
 
-    pub(super) fn line_number_at_offset(&self, byte_offset: usize) -> usize {
+    pub(super) fn line_number_at_offset(&self, byte_offset: usize) -> LineNumber {
         let offset = byte_offset.min(self.content_len);
-        1 + self
-            .newline_offsets
-            .partition_point(|&line_break| line_break < offset)
+        LineNumber::from_0_indexed(
+            self.newline_offsets
+                .partition_point(|&line_break| line_break < offset),
+        )
     }
 }
diff --git a/src/copyright/parser.rs b/src/copyright/parser.rs
index 7b722ca67..036f221f3 100644
--- a/src/copyright/parser.rs
+++ b/src/copyright/parser.rs
@@ -8,15 +8,16 @@ use std::time::Instant;
 
 use super::grammar::{GRAMMAR_RULES, GrammarRule, TagMatcher};
 use super::types::{ParseNode, Token};
+use crate::models::LineNumber;
 
-fn first_line(node: &ParseNode) -> Option<usize> {
+fn first_line(node: &ParseNode) -> Option<LineNumber> {
     match node {
         ParseNode::Leaf(t) => Some(t.start_line),
         ParseNode::Tree { children, .. } => children.iter().filter_map(first_line).min(),
     }
 }
 
-fn last_line(node: &ParseNode) -> Option<usize> {
+fn last_line(node: &ParseNode) -> Option<LineNumber> {
     match node {
         ParseNode::Leaf(t) => Some(t.start_line),
         ParseNode::Tree { children, .. } => children.iter().filter_map(last_line).max(),
diff --git a/src/copyright/parser_test.rs b/src/copyright/parser_test.rs
index 394ea74b5..a679b96b8 100644
--- a/src/copyright/parser_test.rs
+++ b/src/copyright/parser_test.rs
@@ -1,11 +1,12 @@
 use super::*;
 use crate::copyright::types::{PosTag, TreeLabel};
+use crate::models::LineNumber;
 
 fn make_token(value: &str, tag: PosTag, line: usize) -> Token {
     Token {
         value: value.to_string(),
         tag,
-        start_line: line,
+        start_line: LineNumber::new(line).unwrap(),
     }
 }
 
diff --git a/src/copyright/types.rs b/src/copyright/types.rs
index 06db17cc2..8ab7ffa35 100644
--- a/src/copyright/types.rs
+++ b/src/copyright/types.rs
@@ -8,37 +8,27 @@
 
 use serde::Serialize;
 
-/// A detected copyright statement with source location.
+use crate::models::LineNumber;
+
 #[derive(Debug, Clone, PartialEq, Serialize)]
 pub struct CopyrightDetection {
-    /// The full copyright text (e.g., "Copyright 2024 Acme Inc.").
     pub copyright: String,
-    /// 1-based line number where this detection starts.
-    pub start_line: usize,
-    /// 1-based line number where this detection ends.
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
-/// A detected copyright holder name with source location.
 #[derive(Debug, Clone, PartialEq, Serialize)]
 pub struct HolderDetection {
-    /// The holder name (e.g., "Acme Inc.").
     pub holder: String,
-    /// 1-based line number where this detection starts.
-    pub start_line: usize,
-    /// 1-based line number where this detection ends.
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
-/// A detected author name with source location.
 #[derive(Debug, Clone, PartialEq, Serialize)]
 pub struct AuthorDetection {
-    /// The author name (e.g., "John Doe").
     pub author: String,
-    /// 1-based line number where this detection starts.
-    pub start_line: usize,
-    /// 1-based line number where this detection ends.
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 /// Part-of-Speech tag for a token (type-safe, not stringly-typed)
@@ -117,15 +107,11 @@ pub enum PosTag {
     Day,   // Day of week
 }
 
-/// A token with its POS tag and source location.
 #[derive(Debug, Clone)]
 pub struct Token {
-    /// The token text (e.g., "Copyright", "2024", "Acme").
     pub value: String,
-    /// The assigned POS tag.
     pub tag: PosTag,
-    /// 1-based source line number.
-    pub start_line: usize,
+    pub start_line: LineNumber,
 }
 
 /// A node in the parse tree
@@ -185,8 +171,8 @@ mod tests {
     fn test_copyright_detection_creation() {
         let d = CopyrightDetection {
             copyright: "Copyright 2024 Acme Inc.".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         };
         assert_eq!(d.copyright, "Copyright 2024 Acme Inc.");
     }
@@ -196,7 +182,7 @@ mod tests {
         let t = Token {
             value: "Copyright".to_string(),
             tag: PosTag::Copy,
-            start_line: 1,
+            start_line: LineNumber::ONE,
         };
         assert_eq!(t.tag, PosTag::Copy);
     }
@@ -206,7 +192,7 @@ mod tests {
         let node = ParseNode::Leaf(Token {
             value: "2024".to_string(),
             tag: PosTag::Yr,
-            start_line: 5,
+            start_line: LineNumber::new(5).unwrap(),
         });
         assert_eq!(node.tag(), Some(PosTag::Yr));
         assert_eq!(node.label(), None);
@@ -217,7 +203,7 @@ mod tests {
         let child = ParseNode::Leaf(Token {
             value: "2024".to_string(),
             tag: PosTag::Yr,
-            start_line: 3,
+            start_line: LineNumber::new(3).unwrap(),
         });
         let tree = ParseNode::Tree {
             label: TreeLabel::YrRange,
diff --git a/src/finder/emails.rs b/src/finder/emails.rs
index 9eb220335..05c4bf3e3 100644
--- a/src/finder/emails.rs
+++ b/src/finder/emails.rs
@@ -1,6 +1,8 @@
 use regex::Regex;
 use std::sync::LazyLock;
 
+use crate::models::LineNumber;
+
 use super::DetectionConfig;
 use super::host::is_good_email_domain;
 use super::junk_data::classify_email;
@@ -8,8 +10,8 @@ use super::junk_data::classify_email;
 #[derive(Debug, Clone, PartialEq)]
 pub struct EmailDetection {
     pub email: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 static EMAILS_REGEX: LazyLock<Regex> = LazyLock::new(|| {
@@ -20,7 +22,7 @@ pub fn find_emails(text: &str, config: &DetectionConfig) -> Vec<EmailDetection>
     let mut detections = Vec::new();
 
     for (line_index, line) in text.lines().enumerate() {
-        let line_number = line_index + 1;
+        let line_number = LineNumber::from_0_indexed(line_index);
         for matched in EMAILS_REGEX.find_iter(line) {
             let email = matched.as_str().to_lowercase();
             if !is_good_email_domain(&email) {
diff --git a/src/finder/golden_test.rs b/src/finder/golden_test.rs
index 29f6f23b7..30be4d416 100644
--- a/src/finder/golden_test.rs
+++ b/src/finder/golden_test.rs
@@ -59,8 +59,8 @@ mod tests {
             .into_iter()
             .map(|d| ExpectedEmail {
                 email: d.email,
-                start_line: d.start_line,
-                end_line: d.end_line,
+                start_line: d.start_line.get(),
+                end_line: d.end_line.get(),
             })
             .collect()
     }
@@ -70,8 +70,8 @@ mod tests {
             .into_iter()
             .map(|d| ExpectedUrl {
                 url: d.url,
-                start_line: d.start_line,
-                end_line: d.end_line,
+                start_line: d.start_line.get(),
+                end_line: d.end_line.get(),
             })
             .collect()
     }
diff --git a/src/finder/mod.rs b/src/finder/mod.rs
index 5ab9fcefe..8203985e0 100644
--- a/src/finder/mod.rs
+++ b/src/finder/mod.rs
@@ -28,6 +28,7 @@ impl Default for DetectionConfig {
 #[cfg(test)]
 mod tests {
     use super::{DetectionConfig, find_emails, find_urls};
+    use crate::models::LineNumber;
 
     #[test]
     fn test_find_emails_threshold() {
@@ -39,7 +40,7 @@ mod tests {
         let emails = find_emails(text, &config);
         assert_eq!(emails.len(), 2);
         assert_eq!(emails[0].email, "a@b.com");
-        assert_eq!(emails[0].start_line, 1);
+        assert_eq!(emails[0].start_line, LineNumber::ONE);
     }
 
     #[test]
diff --git a/src/finder/urls.rs b/src/finder/urls.rs
index 1b24e3b2a..976d274d6 100644
--- a/src/finder/urls.rs
+++ b/src/finder/urls.rs
@@ -3,6 +3,8 @@ use std::sync::LazyLock;
 
 use url::Url;
 
+use crate::models::LineNumber;
+
 use super::DetectionConfig;
 use super::host::is_good_url_host_domain;
 use super::junk_data::classify_url;
@@ -10,8 +12,8 @@ use super::junk_data::classify_url;
 #[derive(Debug, Clone, PartialEq)]
 pub struct UrlDetection {
     pub url: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 static URLS_REGEX: LazyLock<Regex> = LazyLock::new(|| {
@@ -114,7 +116,7 @@ pub fn find_urls(text: &str, config: &DetectionConfig) -> Vec<UrlDetection> {
     let mut detections = Vec::new();
 
     for (line_index, line) in text.lines().enumerate() {
-        let line_number = line_index + 1;
+        let line_number = LineNumber::from_0_indexed(line_index);
         let normalized_line = line.replace("\\r\\n", "\\n").replace("\\r", "\\n");
 
         for segment in normalized_line.split("\\n") {
diff --git a/src/license_detection/aho_match.rs b/src/license_detection/aho_match.rs
index 76b773ac6..294ef4a3a 100644
--- a/src/license_detection/aho_match.rs
+++ b/src/license_detection/aho_match.rs
@@ -13,6 +13,7 @@ use crate::license_detection::models::position_span::PositionSpan;
 use crate::license_detection::models::{LicenseMatch, MatchCoordinates, MatcherKind};
 use crate::license_detection::position_set::PositionSet;
 use crate::license_detection::query::QueryRun;
+use crate::models::LineNumber;
 
 pub const MATCH_AHO: MatcherKind = MatcherKind::Aho;
 
@@ -130,12 +131,15 @@ pub fn aho_match_with_extra_matchables(
                 100.0
             };
 
-            let start_line = query_run.line_for_pos(qstart).unwrap_or(1);
+            let start_line = query_run
+                .line_for_pos(qstart)
+                .and_then(LineNumber::new)
+                .unwrap_or(LineNumber::ONE);
 
             let end_line = if qend > qstart {
-                // qend is exclusive, so the last matched token is at qend-1
                 query_run
                     .line_for_pos(qend.saturating_sub(1))
+                    .and_then(LineNumber::new)
                     .unwrap_or(start_line)
             } else {
                 start_line
@@ -604,8 +608,8 @@ mod tests {
         let matches = aho_match(run.get_index(), &run);
 
         assert_eq!(matches.len(), 1);
-        assert_eq!(matches[0].start_line, 5);
-        assert_eq!(matches[0].end_line, 5);
+        assert_eq!(matches[0].start_line, LineNumber::new(5).expect("valid"));
+        assert_eq!(matches[0].end_line, LineNumber::new(5).expect("valid"));
     }
 
     #[test]
diff --git a/src/license_detection/detection/analysis.rs b/src/license_detection/detection/analysis.rs
index 92ad7a54b..7e3ff6204 100644
--- a/src/license_detection/detection/analysis.rs
+++ b/src/license_detection/detection/analysis.rs
@@ -90,7 +90,12 @@ pub(super) fn is_false_positive(matches: &[LicenseMatch]) -> bool {
         return false;
     }
 
-    let start_line = matches.iter().map(|m| m.start_line).min().unwrap_or(0);
+    let start_line = matches
+        .iter()
+        .map(|m| m.start_line)
+        .min()
+        .map(|ln| ln.get())
+        .unwrap_or(0);
 
     let bare_rules = ["gpl_bare", "freeware_bare", "public-domain_bare"];
     let is_bare_rule = matches.iter().all(|m| {
@@ -533,8 +538,18 @@ fn has_alternative_license_notice(matches: &[LicenseMatch], source_text: Option<
         return false;
     };
 
-    let start_line = matches.iter().map(|m| m.start_line).min().unwrap_or(0);
-    let end_line = matches.iter().map(|m| m.end_line).max().unwrap_or(0);
+    let start_line = matches
+        .iter()
+        .map(|m| m.start_line)
+        .min()
+        .map(|ln| ln.get())
+        .unwrap_or(0);
+    let end_line = matches
+        .iter()
+        .map(|m| m.end_line)
+        .max()
+        .map(|ln| ln.get())
+        .unwrap_or(0);
     if start_line == 0 || end_line < start_line {
         return false;
     }
@@ -597,6 +612,7 @@ mod tests {
     use crate::license_detection::models::{
         LicenseMatch, MatchCoordinates, MatcherKind, PositionSpan,
     };
+    use crate::models::LineNumber;
 
     fn create_test_match(coverage: f32, rule_identifier: &str) -> LicenseMatch {
         LicenseMatch {
@@ -604,8 +620,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).expect("valid line number"),
             start_token: 1,
             end_token: 11,
             matcher: crate::license_detection::models::MatcherKind::Hash,
@@ -640,6 +656,8 @@ mod tests {
         rule_relevance: u8,
         rule_identifier: &str,
     ) -> LicenseMatch {
+        let start_line = LineNumber::new(start_line).expect("valid start_line");
+        let end_line = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid: 0,
             license_expression: license_expression.to_string(),
@@ -647,8 +665,8 @@ mod tests {
             from_file: Some("test.txt".to_string()),
             start_line,
             end_line,
-            start_token: start_line,
-            end_token: end_line + 1,
+            start_token: start_line.get(),
+            end_token: end_line.get() + 1,
             matcher: matcher.parse().expect("invalid test matcher"),
             score,
             matched_length,
@@ -663,8 +681,8 @@ mod tests {
             is_from_license: false,
             rule_start_token: 0,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(
-                start_line,
-                end_line + 1,
+                start_line.get(),
+                end_line.get() + 1,
             )),
             candidate_resemblance: 0.0,
             candidate_containment: 0.0,
diff --git a/src/license_detection/detection/grouping.rs b/src/license_detection/detection/grouping.rs
index 203288db9..f68b57162 100644
--- a/src/license_detection/detection/grouping.rs
+++ b/src/license_detection/detection/grouping.rs
@@ -78,7 +78,7 @@ pub(super) fn should_group_together(
     cur: &LicenseMatch,
     threshold: usize,
 ) -> bool {
-    let line_gap = cur.start_line.saturating_sub(prev.end_line);
+    let line_gap = cur.start_line.get().saturating_sub(prev.end_line.get());
     line_gap <= threshold
 }
 
@@ -132,6 +132,7 @@ pub(super) fn is_correct_detection(matches: &[LicenseMatch]) -> bool {
 mod tests {
     use super::*;
     use crate::license_detection::models::{LicenseMatch, MatchCoordinates, PositionSpan};
+    use crate::models::LineNumber;
 
     fn create_test_match(
         start_line: usize,
@@ -139,13 +140,15 @@ mod tests {
         matcher: &str,
         rule_identifier: &str,
     ) -> LicenseMatch {
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid: 0,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token: start_line,
             end_token: end_line + 1,
             matcher: matcher.parse().expect("invalid test matcher"),
@@ -176,13 +179,15 @@ mod tests {
         start_token: usize,
         end_token: usize,
     ) -> LicenseMatch {
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid: 0,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token,
             end_token,
             matcher: crate::license_detection::models::MatcherKind::Hash,
diff --git a/src/license_detection/detection/identifier.rs b/src/license_detection/detection/identifier.rs
index 6112e3f99..62bbef9a4 100644
--- a/src/license_detection/detection/identifier.rs
+++ b/src/license_detection/detection/identifier.rs
@@ -162,6 +162,7 @@ pub(super) fn compute_detection_coverage(matches: &[LicenseMatch]) -> f32 {
 mod tests {
     use super::*;
     use crate::license_detection::models::{LicenseMatch, MatchCoordinates, PositionSpan};
+    use crate::models::LineNumber;
 
     fn create_test_match() -> LicenseMatch {
         LicenseMatch {
@@ -169,8 +170,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).expect("valid line number"),
             start_token: 1,
             end_token: 11,
             matcher: crate::license_detection::models::MatcherKind::Hash,
diff --git a/src/license_detection/detection/mod.rs b/src/license_detection/detection/mod.rs
index a5565295e..0ef0182b4 100644
--- a/src/license_detection/detection/mod.rs
+++ b/src/license_detection/detection/mod.rs
@@ -234,7 +234,11 @@ pub(crate) fn get_unique_detections(detections: &[LicenseDetection]) -> Vec<Uniq
             });
 
         for region in &detection.file_regions {
-            let key = (region.path.clone(), region.start_line, region.end_line);
+            let key = (
+                region.path.clone(),
+                region.start_line.get(),
+                region.end_line.get(),
+            );
             if seen_regions.insert(key) {
                 entry.file_regions.push(region.clone());
             }
@@ -443,8 +447,20 @@ pub fn rank_detections(mut detections: Vec<LicenseDetection>) -> Vec<LicenseDete
 /// earlier in the file come first in the results.
 pub fn sort_detections_by_line(mut detections: Vec<LicenseDetection>) -> Vec<LicenseDetection> {
     detections.sort_by(|a, b| {
-        let min_line_a = a.matches.iter().map(|m| m.start_line).min().unwrap_or(0);
-        let min_line_b = b.matches.iter().map(|m| m.start_line).min().unwrap_or(0);
+        let min_line_a = a
+            .matches
+            .iter()
+            .map(|m| m.start_line)
+            .min()
+            .map(|ln| ln.get())
+            .unwrap_or(0);
+        let min_line_b = b
+            .matches
+            .iter()
+            .map(|m| m.start_line)
+            .min()
+            .map(|ln| ln.get())
+            .unwrap_or(0);
         min_line_a
             .cmp(&min_line_b)
             .then_with(|| a.identifier.cmp(&b.identifier))
@@ -568,6 +584,7 @@ mod tests {
     use super::*;
     use crate::license_detection::models::{License, LicenseMatch, MatchCoordinates, PositionSpan};
     use crate::license_detection::spdx_mapping::build_spdx_mapping;
+    use crate::models::LineNumber;
 
     fn create_test_match(
         start_line: usize,
@@ -575,13 +592,15 @@ mod tests {
         matcher: &str,
         rule_identifier: &str,
     ) -> LicenseMatch {
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid: 0,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token: start_line,
             end_token: end_line + 1,
             matcher: matcher.parse().expect("invalid test matcher"),
@@ -1387,8 +1406,11 @@ mod tests {
             file_regions: Vec::new(),
         };
         let sorted = sort_detections_by_line(vec![d1, d2]);
-        assert_eq!(sorted[0].matches[0].start_line, 1);
-        assert_eq!(sorted[1].matches[0].start_line, 20);
+        assert_eq!(sorted[0].matches[0].start_line, LineNumber::ONE);
+        assert_eq!(
+            sorted[1].matches[0].start_line,
+            LineNumber::new(20).expect("valid")
+        );
     }
 
     #[test]
@@ -1532,8 +1554,14 @@ mod tests {
         );
         assert_eq!(detections[0].file_regions.len(), 1);
         assert_eq!(detections[0].file_regions[0].path, "src/lib.rs");
-        assert_eq!(detections[0].file_regions[0].start_line, 4);
-        assert_eq!(detections[0].file_regions[0].end_line, 8);
+        assert_eq!(
+            detections[0].file_regions[0].start_line,
+            LineNumber::new(4).expect("valid")
+        );
+        assert_eq!(
+            detections[0].file_regions[0].end_line,
+            LineNumber::new(8).expect("valid")
+        );
     }
 
     #[test]
@@ -1555,8 +1583,14 @@ mod tests {
 
         assert_eq!(detections[0].file_regions.len(), 1);
         assert_eq!(detections[0].file_regions[0].path, "src/lib.rs");
-        assert_eq!(detections[0].file_regions[0].start_line, 4);
-        assert_eq!(detections[0].file_regions[0].end_line, 25);
+        assert_eq!(
+            detections[0].file_regions[0].start_line,
+            LineNumber::new(4).expect("valid")
+        );
+        assert_eq!(
+            detections[0].file_regions[0].end_line,
+            LineNumber::new(25).expect("valid")
+        );
     }
 
     #[test]
@@ -1569,8 +1603,8 @@ mod tests {
             identifier: Some("mit-shared".to_string()),
             file_regions: vec![FileRegion {
                 path: "src/one.rs".to_string(),
-                start_line: 1,
-                end_line: 10,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(10).expect("valid"),
             }],
         };
         let second = LicenseDetection {
@@ -1581,8 +1615,8 @@ mod tests {
             identifier: Some("mit-shared".to_string()),
             file_regions: vec![FileRegion {
                 path: "src/two.rs".to_string(),
-                start_line: 20,
-                end_line: 30,
+                start_line: LineNumber::new(20).expect("valid"),
+                end_line: LineNumber::new(30).expect("valid"),
             }],
         };
         let third = LicenseDetection {
@@ -1593,8 +1627,8 @@ mod tests {
             identifier: Some("mit-shared".to_string()),
             file_regions: vec![FileRegion {
                 path: "src/two.rs".to_string(),
-                start_line: 20,
-                end_line: 30,
+                start_line: LineNumber::new(20).expect("valid"),
+                end_line: LineNumber::new(30).expect("valid"),
             }],
         };
 
@@ -1615,8 +1649,8 @@ mod tests {
             identifier: None,
             file_regions: vec![FileRegion {
                 path: "src/one.rs".to_string(),
-                start_line: 1,
-                end_line: 10,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(10).expect("valid"),
             }],
         };
 
@@ -1635,8 +1669,8 @@ mod tests {
             identifier: Some("mit-shared".to_string()),
             file_regions: vec![FileRegion {
                 path: "src/one.rs".to_string(),
-                start_line: 1,
-                end_line: 10,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(10).expect("valid"),
             }],
         };
         let second = LicenseDetection {
@@ -1647,8 +1681,8 @@ mod tests {
             identifier: Some("mit-shared".to_string()),
             file_regions: vec![FileRegion {
                 path: "src/two.rs".to_string(),
-                start_line: 20,
-                end_line: 30,
+                start_line: LineNumber::new(20).expect("valid"),
+                end_line: LineNumber::new(30).expect("valid"),
             }],
         };
 
diff --git a/src/license_detection/detection/types.rs b/src/license_detection/detection/types.rs
index 324bf8d61..e518f2b9a 100644
--- a/src/license_detection/detection/types.rs
+++ b/src/license_detection/detection/types.rs
@@ -1,12 +1,13 @@
 //! Core detection data structures.
 
 use crate::license_detection::models::LicenseMatch;
+use crate::models::LineNumber;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub(crate) struct FileRegion {
     pub(crate) path: String,
-    pub(crate) start_line: usize,
-    pub(crate) end_line: usize,
+    pub(crate) start_line: LineNumber,
+    pub(crate) end_line: LineNumber,
 }
 
 #[derive(Debug, Clone)]
@@ -54,15 +55,18 @@ pub struct LicenseDetection {
 mod tests {
     use super::*;
     use crate::license_detection::models::{MatchCoordinates, PositionSpan};
+    use crate::models::LineNumber;
 
     fn create_test_match(start_line: usize, end_line: usize) -> LicenseMatch {
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid: 0,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("test.txt".to_string()),
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token: start_line,
             end_token: end_line + 1,
             matcher: crate::license_detection::models::MatcherKind::Hash,
diff --git a/src/license_detection/hash_match.rs b/src/license_detection/hash_match.rs
index 75329acfe..7c0765ab8 100644
--- a/src/license_detection/hash_match.rs
+++ b/src/license_detection/hash_match.rs
@@ -10,6 +10,7 @@ use crate::license_detection::index::dictionary::{TokenId, TokenKind};
 use crate::license_detection::models::position_span::PositionSpan;
 use crate::license_detection::models::{LicenseMatch, MatchCoordinates, MatcherKind};
 use crate::license_detection::query::QueryRun;
+use crate::models::LineNumber;
 
 pub const MATCH_HASH: MatcherKind = MatcherKind::Hash;
 
@@ -62,9 +63,15 @@ pub fn hash_match(index: &LicenseIndex, query_run: &QueryRun) -> Vec<LicenseMatc
         let matched_length = query_run.tokens().len();
         let match_coverage = 100.0;
 
-        let start_line = query_run.line_for_pos(query_run.start).unwrap_or(1);
+        let start_line = query_run
+            .line_for_pos(query_run.start)
+            .and_then(LineNumber::new)
+            .unwrap_or(LineNumber::ONE);
         let end_line = if let Some(end) = query_run.end {
-            query_run.line_for_pos(end).unwrap_or(start_line)
+            query_run
+                .line_for_pos(end)
+                .and_then(LineNumber::new)
+                .unwrap_or(start_line)
         } else {
             start_line
         };
diff --git a/src/license_detection/match_refine/false_positive.rs b/src/license_detection/match_refine/false_positive.rs
index d4502fda7..18af12fb4 100644
--- a/src/license_detection/match_refine/false_positive.rs
+++ b/src/license_detection/match_refine/false_positive.rs
@@ -170,6 +170,7 @@ pub fn filter_false_positive_license_lists_matches(
 mod tests {
     use super::*;
     use crate::license_detection::models::{MatchCoordinates, PositionSpan};
+    use crate::models::LineNumber;
 
     #[allow(clippy::too_many_arguments)]
     fn create_test_match_with_flags(
@@ -192,8 +193,8 @@ mod tests {
             license_expression: license_expression.to_string(),
             license_expression_spdx: Some(license_expression.to_string()),
             from_file: None,
-            start_line,
-            end_line,
+            start_line: LineNumber::new(start_line).unwrap(),
+            end_line: LineNumber::new(end_line).unwrap(),
             start_token: 0,
             end_token: 0,
             matcher: matcher.parse().expect("invalid test matcher"),
diff --git a/src/license_detection/match_refine/filter_low_quality.rs b/src/license_detection/match_refine/filter_low_quality.rs
index 61c1686e1..52a389153 100644
--- a/src/license_detection/match_refine/filter_low_quality.rs
+++ b/src/license_detection/match_refine/filter_low_quality.rs
@@ -115,7 +115,7 @@ pub(crate) fn filter_short_matches_scattered_on_too_many_lines(
                 && rule.is_small
             {
                 let matched_len = m.len();
-                let line_span = m.end_line.saturating_sub(m.start_line) + 1;
+                let line_span = m.end_line.get().saturating_sub(m.start_line.get()) + 1;
 
                 let effective_matched_len = if rule.is_license_tag() {
                     matched_len + 2
@@ -504,7 +504,7 @@ pub(crate) fn filter_invalid_matches_to_single_word_gibberish(
             {
                 let matched_text = match &m.matched_text {
                     Some(text) => text.clone(),
-                    None => query.matched_text(m.start_line, m.end_line),
+                    None => query.matched_text(m.start_line.get(), m.end_line.get()),
                 };
                 let max_diff = if rule.relevance >= 80 { 1 } else { 0 };
 
@@ -551,6 +551,7 @@ mod tests {
     use crate::license_detection::models::Rule;
     use crate::license_detection::models::position_span::PositionSpan;
     use crate::license_detection::unknown_match::MATCH_UNKNOWN;
+    use crate::models::LineNumber;
 
     fn parse_rule_id(rule_identifier: &str) -> Option<usize> {
         let trimmed = rule_identifier.trim();
@@ -572,13 +573,15 @@ mod tests {
         let matched_len = end_line - start_line + 1;
         let rule_len = matched_len;
         let rid = parse_rule_id(rule_identifier).unwrap_or(0);
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token: start_line,
             end_token: end_line + 1,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -615,8 +618,12 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: start_token,
-            end_line: end_token.saturating_sub(1),
+            start_line: LineNumber::from_0_indexed(start_token),
+            end_line: if end_token == 0 {
+                LineNumber::ONE
+            } else {
+                LineNumber::from_0_indexed(end_token - 1)
+            },
             start_token,
             end_token,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -1150,12 +1157,11 @@ mod tests {
         });
 
         let mut m = create_test_match_with_tokens("#0", 0, 3, 3);
-        m.start_line = 1;
-        m.end_line = 50;
-
-        let mut m2 = create_test_match_with_tokens("#0", 10, 13, 3);
-        m2.start_line = 1;
-        m2.end_line = 50;
+        m.start_line = LineNumber::ONE;
+        m.end_line = LineNumber::new(50).expect("valid");
+        let mut m2 = create_test_match_with_tokens("#0", 0, 3, 3);
+        m2.start_line = LineNumber::ONE;
+        m2.end_line = LineNumber::new(50).expect("valid");
 
         let matches = vec![m, m2];
         let filtered = filter_short_matches_scattered_on_too_many_lines(&index, &matches);
diff --git a/src/license_detection/match_refine/handle_overlaps.rs b/src/license_detection/match_refine/handle_overlaps.rs
index 9bf7cb60d..eca9f94b9 100644
--- a/src/license_detection/match_refine/handle_overlaps.rs
+++ b/src/license_detection/match_refine/handle_overlaps.rs
@@ -428,6 +428,7 @@ mod tests {
     use super::*;
     use crate::license_detection::models::MatchCoordinates;
     use crate::license_detection::models::position_span::PositionSpan;
+    use crate::models::LineNumber;
 
     fn parse_rule_id(rule_identifier: &str) -> Option<usize> {
         let trimmed = rule_identifier.trim();
@@ -449,13 +450,15 @@ mod tests {
         let matched_len = end_line - start_line + 1;
         let rule_len = matched_len;
         let rid = parse_rule_id(rule_identifier).unwrap_or(0);
+        let start_line_ln = LineNumber::new(start_line).expect("valid start_line");
+        let end_line_ln = LineNumber::new(end_line).expect("valid end_line");
         LicenseMatch {
             rid,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line,
-            end_line,
+            start_line: start_line_ln,
+            end_line: end_line_ln,
             start_token: start_line,
             end_token: end_line + 1,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -492,8 +495,12 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: start_token,
-            end_line: end_token.saturating_sub(1),
+            start_line: LineNumber::from_0_indexed(start_token),
+            end_line: if end_token == 0 {
+                LineNumber::ONE
+            } else {
+                LineNumber::from_0_indexed(end_token - 1)
+            },
             start_token,
             end_token,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -529,8 +536,8 @@ mod tests {
         let (filtered, _) = filter_contained_matches(&matches);
 
         assert_eq!(filtered.len(), 1);
-        assert_eq!(filtered[0].start_line, 1);
-        assert_eq!(filtered[0].end_line, 20);
+        assert_eq!(filtered[0].start_line, LineNumber::ONE);
+        assert_eq!(filtered[0].end_line, LineNumber::new(20).expect("valid"));
     }
 
     #[test]
@@ -544,8 +551,8 @@ mod tests {
         let (filtered, _) = filter_contained_matches(&matches);
 
         assert_eq!(filtered.len(), 1);
-        assert_eq!(filtered[0].start_line, 1);
-        assert_eq!(filtered[0].end_line, 30);
+        assert_eq!(filtered[0].start_line, LineNumber::ONE);
+        assert_eq!(filtered[0].end_line, LineNumber::new(30).expect("valid"));
     }
 
     #[test]
@@ -617,7 +624,7 @@ mod tests {
         let (filtered, _) = filter_contained_matches(&matches);
 
         assert_eq!(filtered.len(), 1);
-        assert_eq!(filtered[0].end_line, 30);
+        assert_eq!(filtered[0].end_line, LineNumber::new(30).expect("valid"));
     }
 
     #[test]
@@ -633,8 +640,8 @@ mod tests {
         let (filtered, _) = filter_contained_matches(&matches);
 
         assert_eq!(filtered.len(), 1);
-        assert_eq!(filtered[0].start_line, 1);
-        assert_eq!(filtered[0].end_line, 50);
+        assert_eq!(filtered[0].start_line, LineNumber::ONE);
+        assert_eq!(filtered[0].end_line, LineNumber::new(50).expect("valid"));
     }
 
     #[test]
@@ -745,12 +752,12 @@ mod tests {
     #[test]
     fn test_filter_contained_matches_gpl_variant_zero_tokens() {
         let mut gpl_1_0 = create_test_match_with_tokens("#20560", 0, 0, 9);
-        gpl_1_0.start_line = 13;
-        gpl_1_0.end_line = 14;
+        gpl_1_0.start_line = LineNumber::new(13).expect("valid");
+        gpl_1_0.end_line = LineNumber::new(14).expect("valid");
 
         let mut gpl_2_0 = create_test_match_with_tokens("#16218", 0, 0, 22);
-        gpl_2_0.start_line = 13;
-        gpl_2_0.end_line = 15;
+        gpl_2_0.start_line = LineNumber::new(13).expect("valid");
+        gpl_2_0.end_line = LineNumber::new(15).expect("valid");
 
         let matches = vec![gpl_1_0.clone(), gpl_2_0.clone()];
 
@@ -934,9 +941,9 @@ mod tests {
         let (kept, _) = filter_overlapping_matches(matches, &index);
 
         assert_eq!(kept.len(), 3);
-        assert_eq!(kept[0].start_line, 1);
-        assert_eq!(kept[1].start_line, 25);
-        assert_eq!(kept[2].start_line, 40);
+        assert_eq!(kept[0].start_line, LineNumber::ONE);
+        assert_eq!(kept[1].start_line, LineNumber::new(25).expect("valid"));
+        assert_eq!(kept[2].start_line, LineNumber::new(40).expect("valid"));
     }
 
     #[test]
@@ -1166,8 +1173,8 @@ mod tests {
 
         assert_eq!(to_keep.len(), 1);
         assert_eq!(to_keep[0].rule_identifier, "#2");
-        assert_eq!(to_keep[0].start_line, 50);
-        assert_eq!(to_keep[0].end_line, 65);
+        assert_eq!(to_keep[0].start_line, LineNumber::new(50).expect("valid"));
+        assert_eq!(to_keep[0].end_line, LineNumber::new(65).expect("valid"));
     }
 
     #[test]
diff --git a/src/license_detection/match_refine/merge.rs b/src/license_detection/match_refine/merge.rs
index 953dc4e49..dbc3cd6d6 100644
--- a/src/license_detection/match_refine/merge.rs
+++ b/src/license_detection/match_refine/merge.rs
@@ -369,6 +369,7 @@ mod tests {
     use super::*;
     use crate::license_detection::index::LicenseIndex;
     use crate::license_detection::models::PositionSpan;
+    use crate::models::LineNumber;
 
     fn parse_rule_id(rule_identifier: &str) -> Option<usize> {
         let trimmed = rule_identifier.trim();
@@ -398,8 +399,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line,
-            end_line,
+            start_line: LineNumber::new(start_line).unwrap(),
+            end_line: LineNumber::new(end_line).unwrap(),
             start_token: start_line,
             end_token: end_line + 1,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -434,8 +435,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: start_token,
-            end_line: end_token.saturating_sub(1),
+            start_line: LineNumber::from_0_indexed(start_token),
+            end_line: LineNumber::from_0_indexed(end_token.saturating_sub(1)),
             start_token,
             end_token,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -473,8 +474,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: start_token,
-            end_line: end_token.saturating_sub(1),
+            start_line: LineNumber::from_0_indexed(start_token),
+            end_line: LineNumber::from_0_indexed(end_token.saturating_sub(1)),
             start_token,
             end_token,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -550,8 +551,8 @@ mod tests {
 
         assert_eq!(merged.len(), 1);
         assert_eq!(merged[0].rule_identifier, "#1");
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 15);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(15).unwrap());
         assert_eq!(merged[0].score, 0.9);
     }
 
@@ -580,8 +581,8 @@ mod tests {
 
         assert_eq!(merged.len(), 1);
         assert_eq!(merged[0].rule_identifier, "#1");
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 20);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(20).unwrap());
         assert_eq!(merged[0].score, 0.9);
     }
 
@@ -673,8 +674,8 @@ mod tests {
         let merged = merge_overlapping_matches(&matches);
 
         assert_eq!(merged.len(), 1);
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 15);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(15).unwrap());
     }
 
     #[test]
@@ -689,8 +690,8 @@ mod tests {
         let matches = vec![create_test_match("#1", 1, 10, 0.9, 90.0, 100)];
         let merged = merge_overlapping_matches(&matches);
         assert_eq!(merged.len(), 1);
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 10);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(10).unwrap());
     }
 
     #[test]
@@ -779,8 +780,8 @@ mod tests {
         let merged = merge_overlapping_matches(&matches);
 
         assert_eq!(merged.len(), 1);
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 25);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(25).unwrap());
     }
 
     #[test]
@@ -805,10 +806,10 @@ mod tests {
         let merged = merge_overlapping_matches(&matches);
 
         assert_eq!(merged.len(), 2);
-        assert_eq!(merged[0].start_line, 1);
-        assert_eq!(merged[0].end_line, 10);
-        assert_eq!(merged[1].start_line, 20);
-        assert_eq!(merged[1].end_line, 30);
+        assert_eq!(merged[0].start_line, LineNumber::ONE);
+        assert_eq!(merged[0].end_line, LineNumber::new(10).unwrap());
+        assert_eq!(merged[1].start_line, LineNumber::new(20).unwrap());
+        assert_eq!(merged[1].end_line, LineNumber::new(30).unwrap());
     }
 
     #[test]
diff --git a/src/license_detection/match_refine/mod.rs b/src/license_detection/match_refine/mod.rs
index a0a191039..5565ffc15 100644
--- a/src/license_detection/match_refine/mod.rs
+++ b/src/license_detection/match_refine/mod.rs
@@ -331,6 +331,7 @@ mod tests {
     use super::*;
     use crate::license_detection::models::MatchCoordinates;
     use crate::license_detection::models::position_span::PositionSpan;
+    use crate::models::LineNumber;
 
     fn parse_rule_id(rule_identifier: &str) -> Option<usize> {
         let trimmed = rule_identifier.trim();
@@ -357,8 +358,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line,
-            end_line,
+            start_line: LineNumber::new(start_line).unwrap(),
+            end_line: LineNumber::new(end_line).unwrap(),
             start_token: start_line,
             end_token: end_line + 1,
             matcher: crate::license_detection::models::MatcherKind::Aho,
@@ -425,8 +426,8 @@ mod tests {
         assert_eq!(refined.len(), 2);
 
         let rule1_match = refined.iter().find(|m| m.rule_identifier == "#1").unwrap();
-        assert_eq!(rule1_match.start_line, 1);
-        assert_eq!(rule1_match.end_line, 15);
+        assert_eq!(rule1_match.start_line, LineNumber::ONE);
+        assert_eq!(rule1_match.end_line, LineNumber::new(15).unwrap());
 
         let rule2_match = refined.iter().find(|m| m.rule_identifier == "#2").unwrap();
         assert_eq!(rule2_match.score, 80.0);
@@ -545,8 +546,8 @@ mod tests {
 
         assert_eq!(refined.len(), 1);
         assert_eq!(refined[0].rule_identifier, "#1");
-        assert_eq!(refined[0].start_line, 1);
-        assert_eq!(refined[0].end_line, 20);
+        assert_eq!(refined[0].start_line, LineNumber::ONE);
+        assert_eq!(refined[0].end_line, LineNumber::new(20).unwrap());
     }
 
     #[test]
diff --git a/src/license_detection/models/license_match.rs b/src/license_detection/models/license_match.rs
index e8a0d8b82..0feb3d043 100644
--- a/src/license_detection/models/license_match.rs
+++ b/src/license_detection/models/license_match.rs
@@ -7,6 +7,7 @@ use std::str::FromStr;
 use crate::license_detection::models::RuleKind;
 use crate::license_detection::models::position_span::PositionSpan;
 use crate::license_detection::position_set::PositionSet;
+use crate::models::LineNumber;
 
 /// Coordinate data for a license match.
 ///
@@ -158,10 +159,10 @@ pub struct LicenseMatch {
     pub from_file: Option<String>,
 
     /// Start line number (1-indexed)
-    pub start_line: usize,
+    pub start_line: LineNumber,
 
     /// End line number (1-indexed)
-    pub end_line: usize,
+    pub end_line: LineNumber,
 
     /// Start token position (0-indexed in query token stream)
     /// Used for dual-criteria match grouping with token gap threshold.
@@ -275,8 +276,8 @@ impl Serialize for LicenseMatch {
             license_expression: &self.license_expression,
             license_expression_spdx: &self.license_expression_spdx,
             from_file: &self.from_file,
-            start_line: self.start_line,
-            end_line: self.end_line,
+            start_line: self.start_line.get(),
+            end_line: self.end_line.get(),
             start_token: self.start_token,
             end_token: self.end_token,
             matcher: self.matcher,
@@ -312,8 +313,8 @@ impl Default for LicenseMatch {
             license_expression: String::new(),
             license_expression_spdx: None,
             from_file: None,
-            start_line: 0,
-            end_line: 0,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 0,
             matcher: MatcherKind::default(),
diff --git a/src/license_detection/models/mod_tests.rs b/src/license_detection/models/mod_tests.rs
index 7acca8053..a4067253e 100644
--- a/src/license_detection/models/mod_tests.rs
+++ b/src/license_detection/models/mod_tests.rs
@@ -7,6 +7,7 @@ mod tests {
         License, LicenseMatch, MatchCoordinates, MatcherKind, Rule, RuleKind,
     };
     use crate::license_detection::position_set::PositionSet;
+    use crate::models::LineNumber;
     use crate::models::Match as OutputMatch;
     use std::collections::HashMap;
 
@@ -95,8 +96,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("README.md".to_string()),
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             start_token: 0,
             end_token: 100,
             matcher: crate::license_detection::models::MatcherKind::Hash,
@@ -501,8 +502,8 @@ mod tests {
             Some("MIT".to_string())
         );
         assert_eq!(match_result.from_file, Some("README.md".to_string()));
-        assert_eq!(match_result.start_line, 1);
-        assert_eq!(match_result.end_line, 5);
+        assert_eq!(match_result.start_line, LineNumber::ONE);
+        assert_eq!(match_result.end_line, LineNumber::new(5).unwrap());
         assert_eq!(match_result.matcher, MatcherKind::Hash);
         assert!((match_result.score - 0.95).abs() < 0.001);
     }
@@ -514,8 +515,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: 0,
-            end_line: 0,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 0,
             matcher: MatcherKind::Hash,
@@ -537,7 +538,7 @@ mod tests {
         };
 
         assert!(match_result.from_file.is_none());
-        assert_eq!(match_result.start_line, 0);
+        assert_eq!(match_result.start_line, LineNumber::ONE);
         assert_eq!(match_result.score, 0.0);
         assert!(match_result.matched_text.is_none());
     }
@@ -595,8 +596,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(3),
@@ -622,8 +623,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: Some("README.md".to_string()),
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             start_token: 0,
             end_token: 100,
             matcher: crate::license_detection::models::MatcherKind::Hash,
@@ -881,13 +882,13 @@ mod tests {
     #[test]
     fn test_surround_true() {
         let outer = LicenseMatch {
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             ..create_license_match()
         };
         let inner = LicenseMatch {
-            start_line: 5,
-            end_line: 15,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(15).unwrap(),
             ..create_license_match()
         };
         assert!(outer.surround(&inner));
@@ -896,16 +897,16 @@ mod tests {
     #[test]
     fn test_surround_false_same_start() {
         let outer = LicenseMatch {
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             start_token: 1,
             end_token: 20,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(1, 20)),
             ..create_license_match()
         };
         let inner = LicenseMatch {
-            start_line: 1,
-            end_line: 15,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(15).unwrap(),
             start_token: 1,
             end_token: 15,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(1, 15)),
@@ -917,16 +918,16 @@ mod tests {
     #[test]
     fn test_surround_false_same_end() {
         let outer = LicenseMatch {
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             start_token: 1,
             end_token: 20,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(1, 20)),
             ..create_license_match()
         };
         let inner = LicenseMatch {
-            start_line: 5,
-            end_line: 20,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(20).unwrap(),
             start_token: 5,
             end_token: 20,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(5, 20)),
@@ -938,16 +939,16 @@ mod tests {
     #[test]
     fn test_surround_false_reversed() {
         let outer = LicenseMatch {
-            start_line: 5,
-            end_line: 15,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(15).unwrap(),
             start_token: 5,
             end_token: 15,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(5, 15)),
             ..create_license_match()
         };
         let inner = LicenseMatch {
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             start_token: 1,
             end_token: 20,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(1, 20)),
@@ -959,16 +960,16 @@ mod tests {
     #[test]
     fn test_surround_false_adjacent() {
         let first = LicenseMatch {
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).unwrap(),
             start_token: 1,
             end_token: 10,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(1, 10)),
             ..create_license_match()
         };
         let second = LicenseMatch {
-            start_line: 11,
-            end_line: 20,
+            start_line: LineNumber::new(11).unwrap(),
+            end_line: LineNumber::new(20).unwrap(),
             start_token: 11,
             end_token: 20,
             coordinates: MatchCoordinates::query_region(PositionSpan::range(11, 20)),
diff --git a/src/license_detection/seq_match/matching.rs b/src/license_detection/seq_match/matching.rs
index 491710aec..01c8b80da 100644
--- a/src/license_detection/seq_match/matching.rs
+++ b/src/license_detection/seq_match/matching.rs
@@ -5,6 +5,7 @@ use crate::license_detection::index::dictionary::TokenId;
 use crate::license_detection::models::position_span::PositionSpan;
 use crate::license_detection::models::{LicenseMatch, MatchCoordinates};
 use crate::license_detection::query::QueryRun;
+use crate::models::LineNumber;
 use bit_set::BitSet;
 use std::collections::HashMap;
 
@@ -287,8 +288,14 @@ pub(crate) fn seq_match_with_candidates(
                     let qend = qpos + mlen - 1;
                     let abs_qpos = qpos + query_run.start;
                     let abs_qend = qend + query_run.start;
-                    let start_line = query_run.line_for_pos(abs_qpos).unwrap_or(1);
-                    let end_line = query_run.line_for_pos(abs_qend).unwrap_or(start_line);
+                    let start_line = query_run
+                        .line_for_pos(abs_qpos)
+                        .and_then(LineNumber::new)
+                        .unwrap_or(LineNumber::ONE);
+                    let end_line = query_run
+                        .line_for_pos(abs_qend)
+                        .and_then(LineNumber::new)
+                        .unwrap_or(start_line);
 
                     let qspan =
                         PositionSpan::range(qpos + query_run.start, qpos + mlen + query_run.start);
diff --git a/src/license_detection/seq_match/mod.rs b/src/license_detection/seq_match/mod.rs
index 99facb8c2..8bb5c8a71 100644
--- a/src/license_detection/seq_match/mod.rs
+++ b/src/license_detection/seq_match/mod.rs
@@ -45,6 +45,7 @@ mod tests {
     use crate::license_detection::query::Query;
     use crate::license_detection::test_utils::create_test_index;
     use crate::license_detection::{TokenMultiset, TokenSet};
+    use crate::models::LineNumber;
     use std::collections::HashMap;
 
     pub(super) fn create_seq_match_test_index() -> LicenseIndex {
@@ -277,8 +278,8 @@ mod tests {
             "All matches should be for test-license"
         );
 
-        let start_lines: Vec<usize> = matches.iter().map(|m| m.start_line).collect();
-        let end_lines: Vec<usize> = matches.iter().map(|m| m.end_line).collect();
+        let start_lines: Vec<usize> = matches.iter().map(|m| m.start_line.get()).collect();
+        let end_lines: Vec<usize> = matches.iter().map(|m| m.end_line.get()).collect();
 
         assert!(
             start_lines.iter().all(|&l| l >= 1),
@@ -308,11 +309,13 @@ mod tests {
         let first_match = &matches[0];
 
         assert_eq!(
-            first_match.start_line, 2,
+            first_match.start_line,
+            LineNumber::new(2).unwrap(),
             "Match should start on line 2 (where license tokens are), not line 1"
         );
         assert_eq!(
-            first_match.end_line, 2,
+            first_match.end_line,
+            LineNumber::new(2).unwrap(),
             "Match should end on line 2 (where license tokens are), not line 3"
         );
 
@@ -323,7 +326,8 @@ mod tests {
         );
 
         // Verify we can compute it from the query
-        let matched_text = query.matched_text(first_match.start_line, first_match.end_line);
+        let matched_text =
+            query.matched_text(first_match.start_line.get(), first_match.end_line.get());
         assert!(
             matched_text.contains("license"),
             "Computed matched text should contain 'license'"
@@ -352,11 +356,13 @@ mod tests {
         let first_match = &matches[0];
 
         assert_eq!(
-            first_match.start_line, 2,
+            first_match.start_line,
+            LineNumber::new(2).unwrap(),
             "Partial match should start on line 2"
         );
         assert_eq!(
-            first_match.end_line, 2,
+            first_match.end_line,
+            LineNumber::new(2).unwrap(),
             "Partial match should end on line 2"
         );
 
diff --git a/src/license_detection/spdx_lid/mod.rs b/src/license_detection/spdx_lid/mod.rs
index 64b161d7c..d6f4b104d 100644
--- a/src/license_detection/spdx_lid/mod.rs
+++ b/src/license_detection/spdx_lid/mod.rs
@@ -21,6 +21,7 @@ use crate::license_detection::index::LicenseIndex;
 use crate::license_detection::models::position_span::PositionSpan;
 use crate::license_detection::models::{LicenseMatch, MatchCoordinates, MatcherKind};
 use crate::license_detection::query::Query;
+use crate::models::LineNumber;
 
 pub const MATCH_SPDX_ID: MatcherKind = MatcherKind::SpdxId;
 
@@ -324,10 +325,14 @@ pub fn spdx_lid_match(index: &LicenseIndex, query: &Query) -> Vec<LicenseMatch>
             let matched_length = end_token.saturating_sub(*start_token);
             let match_coverage = 100.0;
 
-            let start_line = query.line_for_pos(*start_token).unwrap_or(1);
+            let start_line = query
+                .line_for_pos(*start_token)
+                .and_then(LineNumber::new)
+                .unwrap_or(LineNumber::ONE);
             let end_line = end_token
                 .checked_sub(1)
                 .and_then(|pos| query.line_for_pos(pos))
+                .and_then(LineNumber::new)
                 .unwrap_or(start_line);
 
             let rid = index
diff --git a/src/license_detection/spdx_lid/test.rs b/src/license_detection/spdx_lid/test.rs
index 1262bb3a8..b6e9d4250 100644
--- a/src/license_detection/spdx_lid/test.rs
+++ b/src/license_detection/spdx_lid/test.rs
@@ -5,6 +5,7 @@ mod tests {
     use crate::license_detection::query::Query;
     use crate::license_detection::spdx_lid::*;
     use crate::license_detection::test_utils::{create_mock_rule_simple, create_test_index};
+    use crate::models::LineNumber;
 
     fn extract_cleaned_spdx_expressions(text: &str) -> Vec<String> {
         text.lines()
@@ -323,8 +324,8 @@ mod tests {
         assert_eq!(matches.len(), 1);
         assert_eq!(matches[0].license_expression, "mit");
         assert_eq!(matches[0].license_expression_spdx, Some("MIT".to_string()));
-        assert_eq!(matches[0].start_line, 1);
-        assert_eq!(matches[0].end_line, 1);
+        assert_eq!(matches[0].start_line, LineNumber::ONE);
+        assert_eq!(matches[0].end_line, LineNumber::ONE);
         assert_eq!(matches[0].matcher, MATCH_SPDX_ID);
         assert_eq!(matches[0].matched_length, 4);
         assert_eq!(matches[0].rule_length, 4);
@@ -429,8 +430,8 @@ mod tests {
         let matches = spdx_lid_match(&index, &query);
 
         assert_eq!(matches.len(), 1);
-        assert_eq!(matches[0].start_line, 1);
-        assert_eq!(matches[0].end_line, 1);
+        assert_eq!(matches[0].start_line, LineNumber::ONE);
+        assert_eq!(matches[0].end_line, LineNumber::ONE);
         assert_eq!(matches[0].matched_length, 3);
         assert_eq!(matches[0].rule_length, 3);
         assert_eq!(matches[0].score, 100.0);
diff --git a/src/license_detection/tests.rs b/src/license_detection/tests.rs
index 5965442de..16ff709bf 100644
--- a/src/license_detection/tests.rs
+++ b/src/license_detection/tests.rs
@@ -3,6 +3,7 @@ use once_cell::sync::Lazy;
 use std::sync::Once;
 
 use crate::license_detection::models::{MatchCoordinates, position_span::PositionSpan};
+use crate::models::LineNumber;
 
 static TEST_ENGINE: Lazy<LicenseDetectionEngine> = Lazy::new(|| {
     LicenseDetectionEngine::from_embedded().expect("Should initialize from embedded artifact")
@@ -462,7 +463,7 @@ fn test_engine_matched_text_populated() {
     for detection in &detections {
         for m in &detection.matches {
             assert!(
-                m.start_line > 0,
+                m.start_line >= LineNumber::ONE,
                 "start_line should be populated for matcher {}",
                 m.matcher
             );
diff --git a/src/license_detection/unknown_match.rs b/src/license_detection/unknown_match.rs
index 202eae13d..eb5b72544 100644
--- a/src/license_detection/unknown_match.rs
+++ b/src/license_detection/unknown_match.rs
@@ -12,6 +12,7 @@ use crate::license_detection::models::{LicenseMatch, MatchCoordinates, MatcherKi
 use crate::license_detection::position_set::PositionSet;
 use crate::license_detection::query::Query;
 use crate::license_detection::tokenize::STOPWORDS;
+use crate::models::LineNumber;
 
 pub const MATCH_UNKNOWN: MatcherKind = MatcherKind::Unknown;
 
@@ -238,11 +239,17 @@ fn create_unknown_match_from_qspan(query: &Query, qspan: &PositionSet) -> Option
     let start = qspan.min_pos();
     let end = qspan.max_pos() + 1;
 
-    let start_line = query.line_by_pos.get(start).copied().unwrap_or(1);
+    let start_line = query
+        .line_by_pos
+        .get(start)
+        .copied()
+        .and_then(LineNumber::new)
+        .unwrap_or(LineNumber::ONE);
     let end_line = query
         .line_by_pos
         .get(end.saturating_sub(1))
         .copied()
+        .and_then(LineNumber::new)
         .unwrap_or(start_line);
 
     let qspan_positions: Vec<usize> = qspan.iter().collect();
@@ -288,8 +295,8 @@ fn create_unknown_match_from_qspan(query: &Query, qspan: &PositionSet) -> Option
 fn build_unknown_rule_text(
     query: &Query,
     qspan_positions: &[usize],
-    start_line: usize,
-    end_line: usize,
+    start_line: LineNumber,
+    end_line: LineNumber,
 ) -> String {
     let Some(&start_pos) = qspan_positions.first() else {
         return String::new();
@@ -305,8 +312,8 @@ fn build_unknown_rule_text(
         &matched_positions,
         start_pos,
         end_pos,
-        start_line,
-        end_line,
+        start_line.get(),
+        end_line.get(),
     );
     let line_endings = collect_line_endings(&query.text);
 
@@ -809,8 +816,8 @@ mod tests {
             license_expression: "test".to_string(),
             license_expression_spdx: Some("TEST".to_string()),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 10,
             matcher: MatcherKind::Aho,
@@ -858,8 +865,8 @@ mod tests {
             license_expression: "test".to_string(),
             license_expression_spdx: Some("TEST".to_string()),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 5,
             end_token: 10,
             matcher: MatcherKind::Aho,
@@ -906,8 +913,8 @@ mod tests {
             license_expression: "test".to_string(),
             license_expression_spdx: Some("TEST".to_string()),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 15,
             matcher: MatcherKind::Aho,
@@ -989,8 +996,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 5,
             matcher: MatcherKind::Aho,
@@ -1014,7 +1021,7 @@ mod tests {
         let matches = unknown_match(&index, &query, &known_matches);
 
         assert!(
-            matches.is_empty() || matches[0].start_line > 1,
+            matches.is_empty() || matches[0].start_line > LineNumber::ONE,
             "Should not re-detect known regions"
         );
     }
diff --git a/src/main_test.rs b/src/main_test.rs
index 2678ad4ca..ceb9635c3 100644
--- a/src/main_test.rs
+++ b/src/main_test.rs
@@ -1,4 +1,5 @@
 use super::*;
+use crate::models::LineNumber;
 use clap::Parser;
 use serde_json::json;
 use std::fs;
@@ -317,8 +318,8 @@ fn from_json_loaded_manifest_detections_can_be_recomputed_into_top_level_uniques
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: None,
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -381,8 +382,8 @@ fn from_json_recomputes_top_level_uniques_even_without_shaping_flags() {
                 license_expression: "gpl-2.0-only".to_string(),
                 license_expression_spdx: "GPL-2.0-only".to_string(),
                 from_file: None,
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -447,8 +448,8 @@ fn from_json_recomputes_top_level_outputs_after_manifest_reference_following() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -472,8 +473,8 @@ fn from_json_recomputes_top_level_outputs_after_manifest_reference_following() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(50),
@@ -564,8 +565,8 @@ fn from_json_recomputes_top_level_outputs_after_package_inheritance_following()
             from_file: Some(
                 "venv/lib/python3.11/site-packages/demo-1.0.dist-info/METADATA".to_string(),
             ),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -594,8 +595,8 @@ fn from_json_recomputes_top_level_outputs_after_package_inheritance_following()
             license_expression: "free-unknown".to_string(),
             license_expression_spdx: "LicenseRef-scancode-free-unknown".to_string(),
             from_file: Some("venv/lib/python3.11/site-packages/locale/django.po".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(11),
diff --git a/src/models/file_info.rs b/src/models/file_info.rs
index c61ee97c6..ec1cc21ec 100644
--- a/src/models/file_info.rs
+++ b/src/models/file_info.rs
@@ -11,6 +11,7 @@ use sha1::{Digest, Sha1};
 
 use super::DatasourceId;
 use super::GitSha1;
+use super::LineNumber;
 use super::Md5Digest;
 use super::PackageType;
 use super::Sha1Digest;
@@ -677,8 +678,8 @@ pub struct Match {
     pub license_expression_spdx: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub from_file: Option<String>,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub matcher: Option<String>,
     pub score: f64,
@@ -702,22 +703,22 @@ pub struct Match {
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Copyright {
     pub copyright: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Holder {
     pub holder: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Author {
     pub author: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 /// Package dependency information with version constraints.
@@ -1291,8 +1292,8 @@ mod tests {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: None,
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                     matcher: Some("parser-declared-license".to_string()),
                     score: 100.0,
                     matched_length: Some(1),
@@ -1369,8 +1370,8 @@ mod tests {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: None,
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                     matcher: Some("parser-declared-license".to_string()),
                     score: 100.0,
                     matched_length: Some(1),
@@ -1620,15 +1621,15 @@ pub fn build_package_uid(purl: &str) -> String {
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct OutputEmail {
     pub email: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct OutputURL {
     pub url: String,
-    pub start_line: usize,
-    pub end_line: usize,
+    pub start_line: LineNumber,
+    pub end_line: LineNumber,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
diff --git a/src/models/line_number.rs b/src/models/line_number.rs
new file mode 100644
index 000000000..54333a61b
--- /dev/null
+++ b/src/models/line_number.rs
@@ -0,0 +1,72 @@
+use std::num::NonZeroUsize;
+use std::ops::{Add, AddAssign, Sub};
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct LineNumber(NonZeroUsize);
+
+impl LineNumber {
+    pub const ONE: Self = match NonZeroUsize::new(1) {
+        Some(n) => Self(n),
+        None => unreachable!(),
+    };
+
+    pub fn new(n: usize) -> Option<Self> {
+        NonZeroUsize::new(n).map(Self)
+    }
+
+    pub fn from_0_indexed(i: usize) -> Self {
+        Self(NonZeroUsize::new(i + 1).expect("0-indexed line overflow"))
+    }
+
+    pub fn get(self) -> usize {
+        self.0.get()
+    }
+
+    pub fn saturating_add(self, n: usize) -> Self {
+        Self(NonZeroUsize::new(self.0.get().saturating_add(n)).expect("LineNumber overflow"))
+    }
+
+    pub fn saturating_sub(self, n: usize) -> usize {
+        self.0.get().saturating_sub(n)
+    }
+
+    pub fn abs_diff(self, other: Self) -> usize {
+        self.0.get().abs_diff(other.0.get())
+    }
+}
+
+impl Add<usize> for LineNumber {
+    type Output = Self;
+    fn add(self, rhs: usize) -> Self::Output {
+        Self(NonZeroUsize::new(self.0.get() + rhs).expect("LineNumber overflow"))
+    }
+}
+
+impl AddAssign<usize> for LineNumber {
+    fn add_assign(&mut self, rhs: usize) {
+        *self = *self + rhs;
+    }
+}
+
+impl Sub<usize> for LineNumber {
+    type Output = usize;
+    fn sub(self, rhs: usize) -> Self::Output {
+        self.0.get() - rhs
+    }
+}
+
+impl Sub for LineNumber {
+    type Output = usize;
+    fn sub(self, rhs: Self) -> Self::Output {
+        self.0.get() - rhs.0.get()
+    }
+}
+
+impl std::fmt::Display for LineNumber {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
diff --git a/src/models/mod.rs b/src/models/mod.rs
index d2213cba0..16b0e115b 100644
--- a/src/models/mod.rs
+++ b/src/models/mod.rs
@@ -1,6 +1,7 @@
 mod datasource_id;
 mod digest;
 pub(crate) mod file_info;
+mod line_number;
 mod output;
 mod package_type;
 
@@ -11,6 +12,7 @@ pub use file_info::{
     LicenseDetection, LicensePolicyEntry, Match, OutputEmail, OutputURL, Package, PackageData,
     Party, ResolvedPackage, TopLevelDependency,
 };
+pub use line_number::LineNumber;
 pub use package_type::PackageType;
 
 #[cfg(test)]
diff --git a/src/output/debian.rs b/src/output/debian.rs
index 132eb3877..7f7a33e2d 100644
--- a/src/output/debian.rs
+++ b/src/output/debian.rs
@@ -118,7 +118,7 @@ fn unique_license_texts(detections: &[crate::models::LicenseDetection]) -> Vec<&
 #[cfg(test)]
 mod tests {
     use super::{detected_license_expression, unique_license_texts};
-    use crate::models::{FileInfo, FileType, LicenseDetection, Match};
+    use crate::models::{FileInfo, FileType, LicenseDetection, LineNumber, Match};
 
     #[test]
     fn unique_license_texts_deduplicates_by_region_and_rule() {
@@ -130,8 +130,8 @@ mod tests {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: Some("src/lib.rs".to_string()),
-                    start_line: 1,
-                    end_line: 3,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::new(3).unwrap(),
                     matcher: Some("1-hash".to_string()),
                     score: 100.0,
                     matched_length: Some(3),
@@ -147,8 +147,8 @@ mod tests {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: Some("src/lib.rs".to_string()),
-                    start_line: 1,
-                    end_line: 3,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::new(3).unwrap(),
                     matcher: Some("2-aho".to_string()),
                     score: 100.0,
                     matched_length: Some(3),
diff --git a/src/output/html.rs b/src/output/html.rs
index 0db7023f6..b642be87c 100644
--- a/src/output/html.rs
+++ b/src/output/html.rs
@@ -83,8 +83,8 @@ pub(crate) fn write_html_report(output: &Output, writer: &mut dyn Write) -> io::
         for c in &file.copyrights {
             let mut row = BTreeMap::new();
             row.insert("path".to_string(), file.path.clone());
-            row.insert("start".to_string(), c.start_line.to_string());
-            row.insert("end".to_string(), c.end_line.to_string());
+            row.insert("start".to_string(), c.start_line.get().to_string());
+            row.insert("end".to_string(), c.end_line.get().to_string());
             row.insert("what".to_string(), "copyright".to_string());
             row.insert("value".to_string(), c.copyright.clone());
             license_copyright_rows.push(row);
@@ -93,8 +93,8 @@ pub(crate) fn write_html_report(output: &Output, writer: &mut dyn Write) -> io::
             for m in &detection.matches {
                 let mut row = BTreeMap::new();
                 row.insert("path".to_string(), file.path.clone());
-                row.insert("start".to_string(), m.start_line.to_string());
-                row.insert("end".to_string(), m.end_line.to_string());
+                row.insert("start".to_string(), m.start_line.get().to_string());
+                row.insert("end".to_string(), m.end_line.get().to_string());
                 row.insert("what".to_string(), "license".to_string());
                 row.insert("value".to_string(), detection.license_expression.clone());
                 license_copyright_rows.push(row);
@@ -105,32 +105,32 @@ pub(crate) fn write_html_report(output: &Output, writer: &mut dyn Write) -> io::
             let mut row = BTreeMap::new();
             row.insert("path".to_string(), file.path.clone());
             row.insert("holder".to_string(), h.holder.clone());
-            row.insert("start".to_string(), h.start_line.to_string());
-            row.insert("end".to_string(), h.end_line.to_string());
+            row.insert("start".to_string(), h.start_line.get().to_string());
+            row.insert("end".to_string(), h.end_line.get().to_string());
             holder_rows.push(row);
         }
         for a in &file.authors {
             let mut row = BTreeMap::new();
             row.insert("path".to_string(), file.path.clone());
             row.insert("author".to_string(), a.author.clone());
-            row.insert("start".to_string(), a.start_line.to_string());
-            row.insert("end".to_string(), a.end_line.to_string());
+            row.insert("start".to_string(), a.start_line.get().to_string());
+            row.insert("end".to_string(), a.end_line.get().to_string());
             author_rows.push(row);
         }
         for e in &file.emails {
             let mut row = BTreeMap::new();
             row.insert("path".to_string(), file.path.clone());
             row.insert("email".to_string(), e.email.clone());
-            row.insert("start".to_string(), e.start_line.to_string());
-            row.insert("end".to_string(), e.end_line.to_string());
+            row.insert("start".to_string(), e.start_line.get().to_string());
+            row.insert("end".to_string(), e.end_line.get().to_string());
             email_rows.push(row);
         }
         for u in &file.urls {
             let mut row = BTreeMap::new();
             row.insert("path".to_string(), file.path.clone());
             row.insert("url".to_string(), u.url.clone());
-            row.insert("start".to_string(), u.start_line.to_string());
-            row.insert("end".to_string(), u.end_line.to_string());
+            row.insert("start".to_string(), u.start_line.get().to_string());
+            row.insert("end".to_string(), u.end_line.get().to_string());
             url_rows.push(row);
         }
 
diff --git a/src/output/mod.rs b/src/output/mod.rs
index 0ebe33bd2..3c37ebfbd 100644
--- a/src/output/mod.rs
+++ b/src/output/mod.rs
@@ -119,8 +119,8 @@ mod tests {
 
     use crate::models::{
         Author, Copyright, ExtraData, FileInfo, FileType, GitSha1, Header, Holder,
-        LicenseDetection, Match, Md5Digest, OutputEmail, OutputURL, PackageData, Sha256Digest,
-        SystemEnvironment,
+        LicenseDetection, LineNumber, Match, Md5Digest, OutputEmail, OutputURL, PackageData,
+        Sha256Digest, SystemEnvironment,
     };
 
     #[test]
@@ -215,8 +215,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("src/main.rs".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -474,8 +474,8 @@ mod tests {
                 license_expression_spdx: "LicenseRef-scancode-unknown-license-reference"
                     .to_string(),
                 from_file: Some("src/main.rs".to_string()),
-                start_line: 1,
-                end_line: 2,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(2).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(4),
@@ -953,8 +953,8 @@ mod tests {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("src/main.rs".to_string()),
-                start_line: 1,
-                end_line: 3,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(3).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1224,8 +1224,8 @@ mod tests {
                         license_expression: "mit".to_string(),
                         license_expression_spdx: "MIT".to_string(),
                         from_file: None,
-                        start_line: 1,
-                        end_line: 1,
+                        start_line: LineNumber::ONE,
+                        end_line: LineNumber::ONE,
                         matcher: None,
                         score: 100.0,
                         matched_length: None,
@@ -1243,28 +1243,28 @@ mod tests {
                 vec![],
                 vec![Copyright {
                     copyright: "Copyright (c) Example".to_string(),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                 }],
                 vec![Holder {
                     holder: "Example Org".to_string(),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                 }],
                 vec![Author {
                     author: "Jane Doe".to_string(),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                 }],
                 vec![OutputEmail {
                     email: "jane@example.com".to_string(),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                 }],
                 vec![OutputURL {
                     url: "https://example.com".to_string(),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                 }],
                 vec![],
                 vec![],
diff --git a/src/output/spdx.rs b/src/output/spdx.rs
index 0593ee34d..ab58b8b86 100644
--- a/src/output/spdx.rs
+++ b/src/output/spdx.rs
@@ -483,7 +483,7 @@ fn spdx_ids_from_expression(expression: &str) -> Vec<String> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::models::{LicenseDetection, PackageData, PackageType};
+    use crate::models::{LicenseDetection, LineNumber, PackageData, PackageType};
 
     #[test]
     fn spdx_file_license_info_includes_manifest_package_data_detections() {
@@ -522,8 +522,8 @@ mod tests {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: Some("project/Cargo.toml".to_string()),
-                    start_line: 1,
-                    end_line: 1,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::ONE,
                     matcher: Some("parser-declared-license".to_string()),
                     score: 100.0,
                     matched_length: Some(1),
diff --git a/src/parsers/debian.rs b/src/parsers/debian.rs
index aca32da37..3ded837a4 100644
--- a/src/parsers/debian.rs
+++ b/src/parsers/debian.rs
@@ -38,8 +38,8 @@ use packageurl::PackageUrl;
 use regex::Regex;
 
 use crate::models::{
-    DatasourceId, Dependency, FileReference, LicenseDetection, Md5Digest, PackageData, PackageType,
-    Party,
+    DatasourceId, Dependency, FileReference, LicenseDetection, LineNumber, Md5Digest, PackageData,
+    PackageType, Party,
 };
 use crate::parsers::rfc822::{self, Rfc822Metadata};
 use crate::parsers::utils::{read_file_to_string, split_name_email};
@@ -1595,10 +1595,11 @@ fn build_primary_license_detection(
     line_no: usize,
 ) -> LicenseDetection {
     let normalized = normalize_debian_license_name(license_name);
+    let line = LineNumber::new(line_no).unwrap();
 
     build_declared_license_detection(
         &normalized,
-        DeclaredLicenseMatchMetadata::new(&matched_text, line_no, line_no),
+        DeclaredLicenseMatchMetadata::new(&matched_text, line, line),
     )
 }
 
@@ -3268,8 +3269,8 @@ License: LGPL-2.1
             primary.matches[0].matched_text.as_deref(),
             Some("License: GPL-2+")
         );
-        assert_eq!(primary.matches[0].start_line, 47);
-        assert_eq!(primary.matches[0].end_line, 47);
+        assert_eq!(primary.matches[0].start_line, LineNumber::new(47).unwrap());
+        assert_eq!(primary.matches[0].end_line, LineNumber::new(47).unwrap());
     }
 
     #[test]
@@ -3285,12 +3286,12 @@ License: LGPL-2.1
             primary.matches[0].matched_text.as_deref(),
             Some("License: LGPL-2.1")
         );
-        assert_eq!(primary.matches[0].start_line, 11);
+        assert_eq!(primary.matches[0].start_line, LineNumber::new(11).unwrap());
 
         let ordered_lines: Vec<usize> = pkg
             .other_license_detections
             .iter()
-            .map(|detection| detection.matches[0].start_line)
+            .map(|detection| detection.matches[0].start_line.get())
             .collect();
         assert_eq!(ordered_lines, vec![15, 19, 23, 25]);
 
@@ -3333,8 +3334,11 @@ License: LGPL-2.1
             .rev()
             .find(|detection| detection.matches[0].matched_text.as_deref() == Some("License: Zlib"))
             .expect("bottom standalone Zlib license paragraph should be detected");
-        assert_eq!(last_zlib.matches[0].start_line, 732);
-        assert_eq!(last_zlib.matches[0].end_line, 732);
+        assert_eq!(
+            last_zlib.matches[0].start_line,
+            LineNumber::new(732).unwrap()
+        );
+        assert_eq!(last_zlib.matches[0].end_line, LineNumber::new(732).unwrap());
     }
 
     #[test]
@@ -3349,8 +3353,8 @@ License: LGPL-2.1
             primary.matches[0].matched_text.as_deref(),
             Some("License: LGPL-3+ or GPL-2+")
         );
-        assert_eq!(primary.matches[0].start_line, 8);
-        assert_eq!(primary.matches[0].end_line, 8);
+        assert_eq!(primary.matches[0].start_line, LineNumber::new(8).unwrap());
+        assert_eq!(primary.matches[0].end_line, LineNumber::new(8).unwrap());
 
         assert!(pkg.other_license_detections.iter().any(|detection| {
             detection.matches[0].matched_text.as_deref() == Some("License: GPL-2+")
@@ -3368,7 +3372,7 @@ License: LGPL-2.1
             primary.matches[0].matched_text.as_deref(),
             Some("License: GPL-2+")
         );
-        assert_eq!(primary.matches[0].start_line, 7);
+        assert_eq!(primary.matches[0].start_line, LineNumber::new(7).unwrap());
     }
 
     #[test]
diff --git a/src/parsers/license_normalization.rs b/src/parsers/license_normalization.rs
index fcc5801c2..685ff38ba 100644
--- a/src/parsers/license_normalization.rs
+++ b/src/parsers/license_normalization.rs
@@ -7,7 +7,7 @@ use crate::license_detection::expression::{
     LicenseExpression, parse_expression, simplify_expression,
 };
 use crate::license_detection::index::LicenseIndex;
-use crate::models::{LicenseDetection, Match, PackageData};
+use crate::models::{LicenseDetection, LineNumber, Match, PackageData};
 use crate::utils::spdx::{ExpressionRelation, combine_license_expressions_with_relation};
 
 pub(crate) const PARSER_DECLARED_MATCHER: &str = "parser-declared-license";
@@ -46,13 +46,13 @@ impl NormalizedDeclaredLicense {
 #[derive(Debug, Clone, Copy)]
 pub(crate) struct DeclaredLicenseMatchMetadata<'a> {
     pub(crate) matched_text: &'a str,
-    pub(crate) start_line: usize,
-    pub(crate) end_line: usize,
+    pub(crate) start_line: LineNumber,
+    pub(crate) end_line: LineNumber,
     pub(crate) referenced_filenames: Option<&'a [&'a str]>,
 }
 
 impl<'a> DeclaredLicenseMatchMetadata<'a> {
-    pub(crate) fn new(matched_text: &'a str, start_line: usize, end_line: usize) -> Self {
+    pub(crate) fn new(matched_text: &'a str, start_line: LineNumber, end_line: LineNumber) -> Self {
         Self {
             matched_text,
             start_line,
@@ -67,7 +67,7 @@ impl<'a> DeclaredLicenseMatchMetadata<'a> {
     }
 
     pub(crate) fn single_line(matched_text: &'a str) -> Self {
-        Self::new(matched_text, 1, 1)
+        Self::new(matched_text, LineNumber::ONE, LineNumber::ONE)
     }
 }
 
@@ -298,8 +298,8 @@ pub(crate) fn finalize_package_declared_license_references(package_data: &mut Pa
                 license_expression_spdx: "LicenseRef-scancode-unknown-license-reference"
                     .to_string(),
                 from_file: None,
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some(PARSER_DECLARED_MATCHER.to_string()),
                 score: 100.0,
                 matched_length: Some(statement.split_whitespace().count()),
@@ -643,14 +643,21 @@ mod tests {
     fn test_build_declared_license_detection_uses_parser_matcher() {
         let detection = build_declared_license_detection(
             &NormalizedDeclaredLicense::new("mit", "MIT"),
-            DeclaredLicenseMatchMetadata::new("MIT", 4, 4),
+            DeclaredLicenseMatchMetadata::new(
+                "MIT",
+                LineNumber::new(4).unwrap(),
+                LineNumber::new(4).unwrap(),
+            ),
         );
 
         assert_eq!(
             detection.matches[0].matcher.as_deref(),
             Some(PARSER_DECLARED_MATCHER)
         );
-        assert_eq!(detection.matches[0].start_line, 4);
+        assert_eq!(
+            detection.matches[0].start_line,
+            LineNumber::new(4).expect("valid")
+        );
         assert_eq!(detection.matches[0].matched_text.as_deref(), Some("MIT"));
     }
 }
diff --git a/src/post_processing/classify_test.rs b/src/post_processing/classify_test.rs
index 26c491090..b19278841 100644
--- a/src/post_processing/classify_test.rs
+++ b/src/post_processing/classify_test.rs
@@ -2,7 +2,9 @@ use std::fs;
 
 use super::test_utils::{dir, file, package, scan_and_assemble_with_keyfiles};
 use super::*;
-use crate::models::{Copyright, DatasourceId, FileReference, Holder, Match, Package, PackageType};
+use crate::models::{
+    Copyright, DatasourceId, FileReference, Holder, LineNumber, Match, Package, PackageType,
+};
 
 #[test]
 fn classify_key_files_marks_nested_ruby_license_from_file_references() {
@@ -29,13 +31,13 @@ fn classify_key_files_marks_nested_ruby_license_from_file_references() {
     license_file.license_expression = Some("Apache-2.0".to_string());
     license_file.copyrights = vec![Copyright {
         copyright: "Copyright (c) 2019 Chef Software Inc.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     license_file.holders = vec![Holder {
         holder: "Chef Software Inc.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     license_file.license_detections = vec![crate::models::LicenseDetection {
         license_expression: "apache-2.0".to_string(),
@@ -44,8 +46,8 @@ fn classify_key_files_marks_nested_ruby_license_from_file_references() {
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("inspec-6.8.2/inspec-bin/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: None,
             score: 100.0,
             matched_length: Some(161),
diff --git a/src/post_processing/mod.rs b/src/post_processing/mod.rs
index e96b4bc57..2efe6cc2d 100644
--- a/src/post_processing/mod.rs
+++ b/src/post_processing/mod.rs
@@ -550,6 +550,7 @@ fn is_good_match(license_match: &Match) -> bool {
 #[cfg(test)]
 mod tests {
     use super::is_good_match;
+    use crate::models::LineNumber;
     use crate::models::file_info::Match;
 
     fn make_match(score: f64, coverage: Option<f64>, relevance: Option<usize>) -> Match {
@@ -557,8 +558,8 @@ mod tests {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score,
             matched_length: Some(3),
diff --git a/src/post_processing/output_test.rs b/src/post_processing/output_test.rs
index 97595961f..0127cca26 100644
--- a/src/post_processing/output_test.rs
+++ b/src/post_processing/output_test.rs
@@ -6,7 +6,9 @@ use super::*;
 use crate::assembly;
 use crate::license_detection::index::{IndexedRuleMetadata, LicenseIndex};
 use crate::license_detection::models::{License as RuntimeLicense, Rule, RuleKind};
-use crate::models::{Copyright, Holder, Match, Package, PackageData, PackageType, Tallies};
+use crate::models::{
+    Copyright, Holder, LineNumber, Match, Package, PackageData, PackageType, Tallies,
+};
 use crate::scan_result_shaping::normalize_paths;
 use serde_json::json;
 
@@ -120,8 +122,8 @@ fn collect_top_level_license_references_includes_clues_packages_and_sorted_dedup
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 2,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(2).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -140,8 +142,8 @@ fn collect_top_level_license_references_includes_clues_packages_and_sorted_dedup
         license_expression: "unknown-license-reference".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
         matcher: Some("2-aho".to_string()),
         score: 100.0,
         matched_length: Some(4),
@@ -296,8 +298,8 @@ fn collect_top_level_license_references_marks_synthetic_spdx_rules() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-spdx-id".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -346,8 +348,8 @@ fn collect_top_level_license_references_applies_custom_license_url_template() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -411,8 +413,8 @@ fn collect_top_level_license_references_preserves_rule_metadata() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -454,8 +456,8 @@ fn apply_local_file_reference_following_resolves_root_license_file() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -480,8 +482,8 @@ fn apply_local_file_reference_following_resolves_root_license_file() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/src/notice.js".to_string()),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -528,8 +530,8 @@ fn apply_local_file_reference_following_prefers_root_license_for_imperfect_subdi
             license_expression: "npsl-exception-0.95".to_string(),
             license_expression_spdx: "LicenseRef-scancode-npsl-exception-0.95".to_string(),
             from_file: Some("LICENSE".to_string()),
-            start_line: 1,
-            end_line: 582,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(582).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(4720),
@@ -554,8 +556,8 @@ fn apply_local_file_reference_following_prefers_root_license_for_imperfect_subdi
             license_expression: "bsd-new".to_string(),
             license_expression_spdx: "BSD-3-Clause".to_string(),
             from_file: Some("third_party/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 30,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(30).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(150),
@@ -580,8 +582,8 @@ fn apply_local_file_reference_following_prefers_root_license_for_imperfect_subdi
             license_expression: "gpl-1.0-plus OR mit".to_string(),
             license_expression_spdx: "GPL-1.0-or-later OR MIT".to_string(),
             from_file: Some("src/FPEngine.h".to_string()),
-            start_line: 49,
-            end_line: 57,
+            start_line: LineNumber::new(49).unwrap(),
+            end_line: LineNumber::new(57).unwrap(),
             matcher: Some("3-seq".to_string()),
             score: 41.79,
             matched_length: Some(28),
@@ -641,8 +643,8 @@ fn apply_local_file_reference_following_does_not_reuse_followed_license_as_secon
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -669,8 +671,8 @@ fn apply_local_file_reference_following_does_not_reuse_followed_license_as_secon
                 license_expression_spdx: "LicenseRef-scancode-unknown-license-reference"
                     .to_string(),
                 from_file: Some("project/ncat/LICENSE".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(2),
@@ -686,8 +688,8 @@ fn apply_local_file_reference_following_does_not_reuse_followed_license_as_secon
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/LICENSE".to_string()),
-                start_line: 1,
-                end_line: 20,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(20).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(100),
@@ -713,8 +715,8 @@ fn apply_local_file_reference_following_does_not_reuse_followed_license_as_secon
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/ncat/ncat_core.h".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -766,8 +768,8 @@ fn apply_local_file_reference_following_requires_exact_filename_match() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -792,8 +794,8 @@ fn apply_local_file_reference_following_requires_exact_filename_match() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/src/notice.js".to_string()),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -835,8 +837,8 @@ fn apply_local_file_reference_following_does_not_search_unrelated_top_level_dire
             license_expression: "bsd-new".to_string(),
             license_expression_spdx: "BSD-3-Clause".to_string(),
             from_file: Some("libssh2/COPYING".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -861,8 +863,8 @@ fn apply_local_file_reference_following_does_not_search_unrelated_top_level_dire
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("docs/3rd-party-licenses.txt".to_string()),
-            start_line: 10,
-            end_line: 10,
+            start_line: LineNumber::new(10).unwrap(),
+            end_line: LineNumber::new(10).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -907,8 +909,8 @@ fn apply_local_file_reference_following_drops_unknown_intro_from_resolved_target
                 license_expression_spdx: "LicenseRef-scancode-unknown-license-reference"
                     .to_string(),
                 from_file: Some("project/LICENSE".to_string()),
-                start_line: 2,
-                end_line: 2,
+                start_line: LineNumber::new(2).unwrap(),
+                end_line: LineNumber::new(2).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 50.0,
                 matched_length: Some(2),
@@ -930,8 +932,8 @@ fn apply_local_file_reference_following_drops_unknown_intro_from_resolved_target
                 license_expression: "apache-2.0".to_string(),
                 license_expression_spdx: "Apache-2.0".to_string(),
                 from_file: Some("project/LICENSE".to_string()),
-                start_line: 5,
-                end_line: 205,
+                start_line: LineNumber::new(5).unwrap(),
+                end_line: LineNumber::new(205).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(1584),
@@ -957,8 +959,8 @@ fn apply_local_file_reference_following_drops_unknown_intro_from_resolved_target
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/src/notice.js".to_string()),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -1009,8 +1011,8 @@ fn apply_local_file_reference_following_resolves_files_beside_manifest() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/demo.dist-info/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -1036,8 +1038,8 @@ fn apply_local_file_reference_following_resolves_files_beside_manifest() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/demo/__init__.py".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -1080,8 +1082,8 @@ fn apply_package_reference_following_resolves_manifest_origin_local_file() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 5,
-            end_line: 5,
+            start_line: LineNumber::new(5).unwrap(),
+            end_line: LineNumber::new(5).unwrap(),
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -1114,8 +1116,8 @@ fn apply_package_reference_following_resolves_manifest_origin_local_file() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -1165,8 +1167,8 @@ fn apply_package_reference_following_resolves_absolute_rootfs_license_reference(
             license_expression: "gpl-2.0".to_string(),
             license_expression_spdx: "GPL-2.0-only".to_string(),
             from_file: Some("usr/share/common-licenses/GPL-2".to_string()),
-            start_line: 1,
-            end_line: 339,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(339).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(2931),
@@ -1191,8 +1193,8 @@ fn apply_package_reference_following_resolves_absolute_rootfs_license_reference(
             license_expression: "gpl-2.0-plus".to_string(),
             license_expression_spdx: "GPL-2.0-or-later".to_string(),
             from_file: Some("usr/sbin/service".to_string()),
-            start_line: 16,
-            end_line: 31,
+            start_line: LineNumber::new(16).unwrap(),
+            end_line: LineNumber::new(31).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(139),
@@ -1269,8 +1271,8 @@ fn apply_package_reference_following_falls_back_to_root_when_package_missing() {
             license_expression: "gpl-3.0".to_string(),
             license_expression_spdx: "GPL-3.0-only".to_string(),
             from_file: Some("project/COPYING".to_string()),
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(50),
@@ -1295,8 +1297,8 @@ fn apply_package_reference_following_falls_back_to_root_when_package_missing() {
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("project/po/en_US.po".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1338,8 +1340,8 @@ fn apply_package_reference_following_falls_back_past_nested_root_to_repo_root()
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(100),
@@ -1364,8 +1366,8 @@ fn apply_package_reference_following_falls_back_past_nested_root_to_repo_root()
             license_expression: "unknown-license-reference".to_string(),
             license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
             from_file: Some("docs/man-xlate/nmap-id.1".to_string()),
-            start_line: 100,
-            end_line: 100,
+            start_line: LineNumber::new(100).unwrap(),
+            end_line: LineNumber::new(100).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(2),
@@ -1414,8 +1416,8 @@ fn apply_package_reference_following_inherits_license_from_package_context() {
             license_expression: "bsd-new".to_string(),
             license_expression_spdx: "BSD-3-Clause".to_string(),
             from_file: Some("project/PKG-INFO".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 99.0,
             matched_length: Some(5),
@@ -1441,8 +1443,8 @@ fn apply_package_reference_following_inherits_license_from_package_context() {
             license_expression: "free-unknown".to_string(),
             license_expression_spdx: "LicenseRef-scancode-free-unknown".to_string(),
             from_file: Some("project/locale/django.po".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(11),
@@ -1489,8 +1491,8 @@ fn apply_package_reference_following_falls_back_to_root_for_missing_package_refe
             license_expression: "gpl-3.0".to_string(),
             license_expression_spdx: "GPL-3.0-only".to_string(),
             from_file: Some("project/COPYING".to_string()),
-            start_line: 1,
-            end_line: 10,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(10).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(50),
@@ -1515,8 +1517,8 @@ fn apply_package_reference_following_falls_back_to_root_for_missing_package_refe
             license_expression: "free-unknown".to_string(),
             license_expression_spdx: "LicenseRef-scancode-free-unknown".to_string(),
             from_file: Some("project/po/en_US.po".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1565,8 +1567,8 @@ fn apply_package_reference_following_leaves_ambiguous_multi_package_file_unresol
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/a/PKG-INFO".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1591,8 +1593,8 @@ fn apply_package_reference_following_leaves_ambiguous_multi_package_file_unresol
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("project/b/PKG-INFO".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1618,8 +1620,8 @@ fn apply_package_reference_following_leaves_ambiguous_multi_package_file_unresol
             license_expression: "free-unknown".to_string(),
             license_expression_spdx: "LicenseRef-scancode-free-unknown".to_string(),
             from_file: Some("project/shared/locale.po".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(11),
@@ -1661,8 +1663,8 @@ fn collect_top_level_license_detections_groups_file_detections_and_preserves_pat
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 3,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(3).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -1686,8 +1688,8 @@ fn collect_top_level_license_detections_groups_file_detections_and_preserves_pat
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/other.rs".to_string()),
-            start_line: 4,
-            end_line: 6,
+            start_line: LineNumber::new(4).unwrap(),
+            end_line: LineNumber::new(6).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -1711,8 +1713,8 @@ fn collect_top_level_license_detections_groups_file_detections_and_preserves_pat
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("project/src/apache.rs".to_string()),
-            start_line: 1,
-            end_line: 12,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(12).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(120),
@@ -1757,8 +1759,8 @@ fn collect_top_level_license_detections_counts_same_identifier_regions_in_one_fi
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/lib.rs".to_string()),
-                start_line: 1,
-                end_line: 3,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(3).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1780,8 +1782,8 @@ fn collect_top_level_license_detections_counts_same_identifier_regions_in_one_fi
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/lib.rs".to_string()),
-                start_line: 20,
-                end_line: 25,
+                start_line: LineNumber::new(20).unwrap(),
+                end_line: LineNumber::new(25).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(12),
@@ -1816,8 +1818,8 @@ fn collect_top_level_license_detections_deduplicates_identical_regions() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/lib.rs".to_string()),
-                start_line: 1,
-                end_line: 5,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(5).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1839,8 +1841,8 @@ fn collect_top_level_license_detections_deduplicates_identical_regions() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/lib.rs".to_string()),
-                start_line: 1,
-                end_line: 5,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(5).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1874,8 +1876,8 @@ fn collect_top_level_license_detections_recomputes_empty_expression_from_matches
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 3,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(3).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -1910,8 +1912,8 @@ fn collect_top_level_license_detections_includes_package_origin_detections() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: None,
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -1933,8 +1935,8 @@ fn collect_top_level_license_detections_includes_package_origin_detections() {
                 license_expression: "apache-2.0".to_string(),
                 license_expression_spdx: "Apache-2.0".to_string(),
                 from_file: None,
-                start_line: 2,
-                end_line: 2,
+                start_line: LineNumber::new(2).unwrap(),
+                end_line: LineNumber::new(2).unwrap(),
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -1974,8 +1976,8 @@ fn collect_top_level_license_detections_prefers_later_logged_representative() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 3,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(3).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -1999,8 +2001,8 @@ fn collect_top_level_license_detections_prefers_later_logged_representative() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/other.rs".to_string()),
-            start_line: 4,
-            end_line: 6,
+            start_line: LineNumber::new(4).unwrap(),
+            end_line: LineNumber::new(6).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -2370,8 +2372,8 @@ fn create_output_preserves_top_level_license_detections_from_context() {
                     license_expression: "mit".to_string(),
                     license_expression_spdx: "MIT".to_string(),
                     from_file: Some("project/LICENSE".to_string()),
-                    start_line: 1,
-                    end_line: 20,
+                    start_line: LineNumber::ONE,
+                    end_line: LineNumber::new(20).unwrap(),
                     matcher: Some("1-hash".to_string()),
                     score: 100.0,
                     matched_length: Some(20),
@@ -2465,8 +2467,8 @@ fn create_output_gates_summary_tallies_and_generated_sections() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some(license_rel.clone()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -2599,8 +2601,8 @@ fn create_output_score_only_keeps_clarity_without_full_summary_fields() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -2666,8 +2668,8 @@ fn create_output_preserves_file_level_license_clues_in_json_shape() {
         license_expression: "unknown-license-reference".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 1,
-        end_line: 2,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 100.0,
         matched_length: Some(19),
@@ -2844,13 +2846,13 @@ fn create_output_promotes_package_metadata_without_summary_flags() {
     license.for_packages = vec![package_uid.clone()];
     license.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     license.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let package = Package {
         package_uid,
@@ -2922,8 +2924,8 @@ fn create_output_summary_still_resolves_after_strip_root_normalization() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/demo.gemspec".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-spdx-id".to_string()),
             score: 100.0,
             matched_length: Some(1),
diff --git a/src/post_processing/reference_following.rs b/src/post_processing/reference_following.rs
index 9daf3281b..6f1747bcc 100644
--- a/src/post_processing/reference_following.rs
+++ b/src/post_processing/reference_following.rs
@@ -179,7 +179,7 @@ fn public_detection_region_key(
         .iter()
         .map(|match_item| match_item.end_line)
         .max()?;
-    Some((owning_path.to_string(), start_line, end_line))
+    Some((owning_path.to_string(), start_line.get(), end_line.get()))
 }
 
 pub(super) fn build_reference_follow_snapshot(
@@ -1217,7 +1217,7 @@ fn internal_match_to_public(
 #[cfg(test)]
 mod tests {
     use super::{apply_package_reference_following, collect_top_level_license_detections};
-    use crate::models::Match;
+    use crate::models::{LineNumber, Match};
     use crate::post_processing::test_utils::file;
 
     #[test]
@@ -1230,8 +1230,8 @@ mod tests {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/lib.rs".to_string()),
-                start_line: 1,
-                end_line: 3,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(3).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1255,8 +1255,8 @@ mod tests {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/other.rs".to_string()),
-                start_line: 4,
-                end_line: 6,
+                start_line: LineNumber::new(4).unwrap(),
+                end_line: LineNumber::new(6).unwrap(),
                 matcher: Some("1-hash".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
@@ -1316,8 +1316,8 @@ mod tests {
                 license_expression: "ofl-1.1".to_string(),
                 license_expression_spdx: "OFL-1.1".to_string(),
                 from_file: Some("fonts/OFL.txt".to_string()),
-                start_line: 1,
-                end_line: 3,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(3).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(10),
diff --git a/src/post_processing/summary/test.rs b/src/post_processing/summary/test.rs
index f3cd32ab9..ed6580303 100644
--- a/src/post_processing/summary/test.rs
+++ b/src/post_processing/summary/test.rs
@@ -5,7 +5,8 @@ use super::super::package_metadata_promotion::promote_package_metadata_from_key_
 use super::super::test_utils::{dir, file, package};
 use super::*;
 use crate::models::{
-    Copyright, DatasourceId, FileReference, Holder, Match, Package, PackageType, TallyEntry,
+    Copyright, DatasourceId, FileReference, Holder, LineNumber, Match, Package, PackageType,
+    TallyEntry,
 };
 
 #[test]
@@ -38,8 +39,8 @@ fn key_file_license_clues_feed_summary_without_mutating_package_license_provenan
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("inspec-6.8.2/inspec-bin/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 20,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(20).unwrap(),
             matcher: None,
             score: 100.0,
             matched_length: Some(161),
@@ -56,13 +57,13 @@ fn key_file_license_clues_feed_summary_without_mutating_package_license_provenan
     }];
     license_file.copyrights = vec![Copyright {
         copyright: "Copyright (c) 2019 Chef Software Inc.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     license_file.holders = vec![Holder {
         holder: "Chef Software Inc.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut files = vec![metadata_file, license_file];
@@ -111,8 +112,8 @@ fn manifest_declared_license_survives_into_package_and_summary() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("demo/demo.gemspec".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: None,
                 score: 100.0,
                 matched_length: None,
@@ -141,8 +142,8 @@ fn manifest_declared_license_survives_into_package_and_summary() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("demo/demo.gemspec".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-spdx-id".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -194,8 +195,8 @@ fn summary_other_license_expressions_include_license_clues() {
         license_expression: "unknown-spdx".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-spdx".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 65.0,
         matched_length: Some(2),
@@ -232,8 +233,8 @@ fn compute_summary_includes_package_other_license_detections_as_other_expression
                 license_expression: "gpl-2.0-only".to_string(),
                 license_expression_spdx: "GPL-2.0-only".to_string(),
                 from_file: Some("project/package.json".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -279,8 +280,8 @@ fn compute_summary_uses_manifest_package_license_detections_when_file_detections
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/Cargo.toml".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -315,8 +316,8 @@ fn compute_summary_prefers_file_license_detections_over_duplicate_package_data_d
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -366,8 +367,8 @@ fn compute_summary_deduplicates_duplicate_other_license_package_data_entries_per
             license_expression: "gpl-2.0-only".to_string(),
             license_expression_spdx: "GPL-2.0-only".to_string(),
             from_file: Some("project/package.json".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -417,8 +418,8 @@ fn compute_summary_deduplicates_duplicate_primary_package_data_entries_per_file(
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -478,8 +479,8 @@ fn compute_summary_uses_root_prefixed_top_level_key_files() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -562,8 +563,8 @@ fn compute_summary_prefers_package_origin_info_and_preserves_other_tallies() {
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("codebase/apache-2.0.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -591,8 +592,8 @@ fn compute_summary_prefers_package_origin_info_and_preserves_other_tallies() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("codebase/mit.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -627,8 +628,8 @@ fn compute_summary_resolves_joined_primary_license_without_ambiguity() {
     readme.license_expression = Some("apache-2.0 AND (apache-2.0 OR mit)".to_string());
     readme.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut apache = file("codebase/apache-2.0.LICENSE");
@@ -643,8 +644,8 @@ fn compute_summary_resolves_joined_primary_license_without_ambiguity() {
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("codebase/apache-2.0.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -672,8 +673,8 @@ fn compute_summary_resolves_joined_primary_license_without_ambiguity() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("codebase/mit.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -708,8 +709,8 @@ fn compute_summary_penalizes_conflicting_non_key_licenses_without_false_ambiguit
     readme.is_top_level = true;
     readme.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut mit = file("codebase/mit.LICENSE");
@@ -724,8 +725,8 @@ fn compute_summary_penalizes_conflicting_non_key_licenses_without_false_ambiguit
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("codebase/mit.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -750,8 +751,8 @@ fn compute_summary_penalizes_conflicting_non_key_licenses_without_false_ambiguit
             license_expression: "gpl-2.0-only".to_string(),
             license_expression_spdx: "GPL-2.0-only".to_string(),
             from_file: Some("codebase/tests/test_a.py".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -790,13 +791,13 @@ fn compute_summary_uses_package_datafile_holders_before_global_holder_fallback()
     setup_py.holders = vec![
         Holder {
             holder: "Google".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
         Holder {
             holder: "Fraunhofer FKIE".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
     ];
 
@@ -806,8 +807,8 @@ fn compute_summary_uses_package_datafile_holders_before_global_holder_fallback()
     readme.is_top_level = true;
     readme.holders = vec![Holder {
         holder: "Example Corporation".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let summary = compute_summary(&[setup_py, readme], &[package]).expect("summary exists");
@@ -835,8 +836,8 @@ fn compute_summary_prefers_package_copyright_holders_over_package_resource_holde
     nuspec.for_packages = vec![package.package_uid.clone()];
     nuspec.holders = vec![Holder {
         holder: "Different Holder".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let summary = compute_summary(&[nuspec], &[package]).expect("summary exists");
@@ -870,8 +871,8 @@ fn compute_summary_keeps_null_other_license_expressions_when_declared_expression
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(10),
@@ -905,16 +906,16 @@ fn compute_summary_keeps_null_other_holders_and_removes_declared_holder_only() {
     readme.is_top_level = true;
     readme.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut authors = file("project/AUTHORS");
     authors.is_community = true;
     authors.holders = vec![Holder {
         holder: "Demo Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut license = file("project/LICENSE");
@@ -932,14 +933,14 @@ fn compute_summary_keeps_holder_tallies_when_no_declared_holder_exists() {
     let mut source_one = file("project/src/main.c");
     source_one.holders = vec![Holder {
         holder: "Members of the Gmerlin project".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let mut source_two = file("project/src/helper.c");
     source_two.holders = vec![Holder {
         holder: "Members of the Gmerlin project".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let summary = compute_summary(&[source_one, source_two], &[]).expect("summary exists");
     assert_eq!(summary.declared_holder.as_deref(), Some(""));
@@ -954,15 +955,15 @@ fn compute_summary_removes_punctuation_only_holder_variants_from_other_holders()
     readme.is_top_level = true;
     readme.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut notice = file("project/NOTICE");
     notice.holders = vec![Holder {
         holder: "Example Corp".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut license = file("project/LICENSE");
@@ -1053,8 +1054,8 @@ fn compute_summary_combines_package_licenses_when_present_datafile_is_not_key_cl
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("codebase/cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-spdx-id".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -1096,8 +1097,8 @@ fn compute_summary_serializes_empty_declared_holder_when_none_found() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("pip-22.0.4/PKG-INFO".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-spdx-id".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -1131,8 +1132,8 @@ fn compute_summary_joins_multiple_holders_from_single_top_level_license_file() {
             license_expression: "jetty".to_string(),
             license_expression_spdx: "LicenseRef-scancode-jetty".to_string(),
             from_file: Some("codebase/jetty.LICENSE".to_string()),
-            start_line: 1,
-            end_line: 132,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(132).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(996),
@@ -1149,19 +1150,19 @@ fn compute_summary_joins_multiple_holders_from_single_top_level_license_file() {
     }];
     license.copyrights = vec![Copyright {
         copyright: "Copyright Mort Bay and Sun Microsystems.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     license.holders = vec![
         Holder {
             holder: "Mort Bay Consulting Pty. Ltd. (Australia) and others".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
         Holder {
             holder: "Sun Microsystems".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
     ];
     let summary = compute_summary(&[license], &[]).expect("summary exists");
@@ -1182,8 +1183,8 @@ fn compute_score_mode_ignores_package_declared_license_without_key_file_license_
     package_json.for_packages = vec![package.package_uid.clone()];
     package_json.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let files = vec![package_json];
     let indexes = OutputIndexes::build(&files, None, false, OutputIndexMode::Full);
@@ -1205,8 +1206,8 @@ fn compute_score_mode_without_license_text_returns_zero_with_copyright_only() {
     package_json.for_packages = vec![package.package_uid.clone()];
     package_json.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let files = vec![package_json];
     let indexes = OutputIndexes::build(&files, None, false, OutputIndexMode::Full);
@@ -1247,8 +1248,8 @@ fn compute_score_mode_uses_single_joined_expression_without_ambiguity() {
             license_expression: "mit OR apache-2.0".to_string(),
             license_expression_spdx: "MIT OR Apache-2.0".to_string(),
             from_file: Some("no_license_ambiguity/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1265,8 +1266,8 @@ fn compute_score_mode_uses_single_joined_expression_without_ambiguity() {
     }];
     cargo.copyrights = vec![Copyright {
         copyright: "Copyright The Rand Project Developers.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     let mut apache = file("no_license_ambiguity/LICENSE-APACHE");
     apache.is_legal = true;
@@ -1280,8 +1281,8 @@ fn compute_score_mode_uses_single_joined_expression_without_ambiguity() {
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("no_license_ambiguity/LICENSE-APACHE".to_string()),
-            start_line: 1,
-            end_line: 176,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(176).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(1410),
@@ -1308,8 +1309,8 @@ fn compute_score_mode_uses_single_joined_expression_without_ambiguity() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("no_license_ambiguity/LICENSE-MIT".to_string()),
-            start_line: 1,
-            end_line: 18,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(18).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(161),
@@ -1361,8 +1362,8 @@ fn compute_score_mode_does_not_treat_with_expression_as_covering_base_license()
             license_expression: "gpl-2.0 WITH classpath-exception-2.0".to_string(),
             license_expression_spdx: "GPL-2.0-only WITH Classpath-exception-2.0".to_string(),
             from_file: Some("with_exception_ambiguity/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(5),
@@ -1379,8 +1380,8 @@ fn compute_score_mode_does_not_treat_with_expression_as_covering_base_license()
     }];
     manifest.copyrights = vec![Copyright {
         copyright: "Copyright Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut gpl = file("with_exception_ambiguity/LICENSE-GPL");
@@ -1395,8 +1396,8 @@ fn compute_score_mode_does_not_treat_with_expression_as_covering_base_license()
             license_expression: "gpl-2.0".to_string(),
             license_expression_spdx: "GPL-2.0-only".to_string(),
             from_file: Some("with_exception_ambiguity/LICENSE-GPL".to_string()),
-            start_line: 1,
-            end_line: 176,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(176).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(1410),
@@ -1442,8 +1443,8 @@ fn compute_score_mode_scores_nested_manifest_key_file_without_copyright() {
             from_file: Some(
                 "jar/META-INF/maven/org.jboss.logging/jboss-logging/pom.xml".to_string(),
             ),
-            start_line: 1,
-            end_line: 2,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(2).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(16),
@@ -1470,8 +1471,8 @@ fn compute_score_mode_scores_nested_manifest_key_file_without_copyright() {
             license_expression: "apache-2.0".to_string(),
             license_expression_spdx: "Apache-2.0".to_string(),
             from_file: Some("jar/META-INF/LICENSE.txt".to_string()),
-            start_line: 1,
-            end_line: 176,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(176).unwrap(),
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(1410),
diff --git a/src/post_processing/tallies_test.rs b/src/post_processing/tallies_test.rs
index fc2244331..27ce435e6 100644
--- a/src/post_processing/tallies_test.rs
+++ b/src/post_processing/tallies_test.rs
@@ -1,6 +1,8 @@
 use super::test_utils::{dir, file};
 use super::*;
-use crate::models::{Author, Copyright, Holder, Match, PackageData, PackageType, TallyEntry};
+use crate::models::{
+    Author, Copyright, Holder, LineNumber, Match, PackageData, PackageType, TallyEntry,
+};
 
 #[test]
 fn compute_tallies_counts_file_findings_and_missing_values() {
@@ -15,8 +17,8 @@ fn compute_tallies_counts_file_findings_and_missing_values() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/src/lib.rs".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: None,
             score: 100.0,
             matched_length: None,
@@ -33,18 +35,18 @@ fn compute_tallies_counts_file_findings_and_missing_values() {
     }];
     mit_file.copyrights = vec![Copyright {
         copyright: "Copyright (c) Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     mit_file.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     mit_file.authors = vec![Author {
         author: "Alice".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut dual_license_file = file("project/src/main.c");
@@ -59,8 +61,8 @@ fn compute_tallies_counts_file_findings_and_missing_values() {
                 license_expression: "apache-2.0".to_string(),
                 license_expression_spdx: "Apache-2.0".to_string(),
                 from_file: Some("project/src/main.c".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: None,
                 score: 100.0,
                 matched_length: None,
@@ -82,8 +84,8 @@ fn compute_tallies_counts_file_findings_and_missing_values() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/src/main.c".to_string()),
-                start_line: 2,
-                end_line: 2,
+                start_line: LineNumber::new(2).unwrap(),
+                end_line: LineNumber::new(2).unwrap(),
                 matcher: None,
                 score: 100.0,
                 matched_length: None,
@@ -101,18 +103,18 @@ fn compute_tallies_counts_file_findings_and_missing_values() {
     ];
     dual_license_file.copyrights = vec![Copyright {
         copyright: "Copyright (c) Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     dual_license_file.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     dual_license_file.authors = vec![Author {
         author: "Bob".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let empty_file = file("project/README.md");
@@ -150,13 +152,13 @@ fn compute_key_file_tallies_only_counts_key_files_and_drops_missing_values() {
     key_license.license_expression = Some("apache-2.0".to_string());
     key_license.copyrights = vec![Copyright {
         copyright: "Copyright (c) Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     key_license.holders = vec![Holder {
         holder: "Example Corp.".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut key_readme = file("project/README.md");
@@ -164,8 +166,8 @@ fn compute_key_file_tallies_only_counts_key_files_and_drops_missing_values() {
     key_readme.programming_language = Some("Markdown".to_string());
     key_readme.authors = vec![Author {
         author: "Alice".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let mut non_key_source = file("project/src/lib.rs");
@@ -203,8 +205,8 @@ fn compute_tallies_include_package_other_license_detections() {
                 license_expression: "gpl-2.0-only".to_string(),
                 license_expression_spdx: "GPL-2.0-only".to_string(),
                 from_file: Some("project/package.json".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -239,8 +241,8 @@ fn compute_tallies_include_license_clues_in_detected_license_expression() {
         license_expression: "unknown-spdx".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-spdx".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 65.0,
         matched_length: Some(2),
@@ -272,8 +274,8 @@ fn compute_key_file_tallies_include_license_clues() {
         license_expression: "unknown-spdx".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-spdx".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 65.0,
         matched_length: Some(2),
@@ -310,8 +312,8 @@ fn compute_key_file_tallies_include_package_other_license_detections() {
                 license_expression: "gpl-2.0-only".to_string(),
                 license_expression_spdx: "GPL-2.0-only".to_string(),
                 from_file: Some("project/package.json".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -349,8 +351,8 @@ fn compute_tallies_include_manifest_package_license_detections() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/Cargo.toml".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -390,8 +392,8 @@ fn compute_key_file_tallies_include_manifest_package_license_detections() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/Cargo.toml".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(1),
@@ -426,8 +428,8 @@ fn compute_tallies_do_not_double_count_duplicate_file_and_package_detections() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -474,8 +476,8 @@ fn compute_tallies_deduplicate_duplicate_package_data_entries_per_file() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/Cargo.toml".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("parser-declared-license".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -536,18 +538,18 @@ fn compute_tallies_ignores_legal_file_copyright_holder_and_author_noise() {
     legal.is_legal = true;
     legal.copyrights = vec![Copyright {
         copyright: "copyright and related or neighboring rights".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     legal.holders = vec![Holder {
         holder: "Related Rights".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     legal.authors = vec![Author {
         author: "be liable for".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let tallies = compute_tallies(&[legal]).expect("tallies exist");
@@ -583,13 +585,13 @@ fn compute_key_file_tallies_excludes_legal_file_copyrights_holders_and_languages
     legal.programming_language = Some("Text".to_string());
     legal.copyrights = vec![Copyright {
         copyright: "copyright and related or neighboring rights".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     legal.holders = vec![Holder {
         holder: "Related Rights".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     assert!(compute_key_file_tallies(&[legal]).is_none());
@@ -600,14 +602,14 @@ fn compute_tallies_normalizes_jboss_style_copyright_and_holder_values() {
     let mut source = file("project/src/lib.java");
     source.copyrights = vec![Copyright {
         copyright: "Copyright 2005, JBoss Inc., and individual contributors as indicated by the @authors tag".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     source.holders = vec![Holder {
         holder: "JBoss Inc., and individual contributors as indicated by the @authors tag"
             .to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let tallies = compute_tallies(&[source]).expect("tallies exist");
@@ -627,8 +629,8 @@ fn compute_tallies_strips_leading_years_from_copyright_tallies() {
     let mut source = file("project/src/zlib.h");
     source.copyrights = vec![Copyright {
         copyright: "Copyright (c) 1995-2013 Jean-loup Gailly and Mark Adler".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let tallies = compute_tallies(&[source]).expect("tallies exist");
@@ -644,8 +646,8 @@ fn compute_tallies_filters_lowercase_author_noise() {
     let mut source = file("project/src/lib.java");
     source.authors = vec![Author {
         author: "be liable for".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     let tallies = compute_tallies(&[source]).expect("tallies exist");
@@ -673,8 +675,8 @@ fn compute_detailed_tallies_assigns_file_and_directory_rollups() {
     files[3].programming_language = Some("Rust".to_string());
     files[3].authors = vec![Author {
         author: "Alice".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     files[4].programming_language = Some("Markdown".to_string());
 
diff --git a/src/scan_result_shaping/core_test.rs b/src/scan_result_shaping/core_test.rs
index ccbb31f10..e717fb650 100644
--- a/src/scan_result_shaping/core_test.rs
+++ b/src/scan_result_shaping/core_test.rs
@@ -1,7 +1,7 @@
 use super::*;
 use crate::models::{
-    Author, Copyright, DatasourceId, Dependency, FileReference, OutputEmail, OutputURL, Package,
-    PackageData, TopLevelDependency,
+    Author, Copyright, DatasourceId, Dependency, FileReference, LineNumber, OutputEmail, OutputURL,
+    Package, PackageData, TopLevelDependency,
 };
 use crate::scan_result_shaping::test_fixtures::{dir, file};
 use regex::Regex;
@@ -50,8 +50,8 @@ fn only_findings_keeps_file_with_findings_and_parent_dirs() {
     let mut files = vec![dir("project"), file("project/a.txt"), file("project/b.txt")];
     files[2].copyrights = vec![Copyright {
         copyright: "Copyright Example".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
 
     apply_only_findings_filter(&mut files);
@@ -68,37 +68,37 @@ fn filter_redundant_clues_dedupes_exact_duplicates() {
     files[0].authors = vec![
         Author {
             author: "Jane".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
         Author {
             author: "Jane".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
     ];
     files[0].emails = vec![
         OutputEmail {
             email: "a@example.com".to_string(),
-            start_line: 3,
-            end_line: 3,
+            start_line: LineNumber::new(3).unwrap(),
+            end_line: LineNumber::new(3).unwrap(),
         },
         OutputEmail {
             email: "a@example.com".to_string(),
-            start_line: 3,
-            end_line: 3,
+            start_line: LineNumber::new(3).unwrap(),
+            end_line: LineNumber::new(3).unwrap(),
         },
     ];
     files[0].urls = vec![
         OutputURL {
             url: "https://example.com".to_string(),
-            start_line: 4,
-            end_line: 4,
+            start_line: LineNumber::new(4).unwrap(),
+            end_line: LineNumber::new(4).unwrap(),
         },
         OutputURL {
             url: "https://example.com".to_string(),
-            start_line: 4,
-            end_line: 4,
+            start_line: LineNumber::new(4).unwrap(),
+            end_line: LineNumber::new(4).unwrap(),
         },
     ];
 
@@ -115,25 +115,25 @@ fn filter_redundant_clues_keeps_distinct_line_ranges_and_dedupes_copyrights_and_
     files[0].copyrights = vec![
         Copyright {
             copyright: "Copyright Example".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
         Copyright {
             copyright: "Copyright Example".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         },
     ];
     files[0].holders = vec![
         crate::models::Holder {
             holder: "Example Corp".to_string(),
-            start_line: 2,
-            end_line: 2,
+            start_line: LineNumber::new(2).unwrap(),
+            end_line: LineNumber::new(2).unwrap(),
         },
         crate::models::Holder {
             holder: "Example Corp".to_string(),
-            start_line: 3,
-            end_line: 3,
+            start_line: LineNumber::new(3).unwrap(),
+            end_line: LineNumber::new(3).unwrap(),
         },
     ];
 
@@ -153,8 +153,8 @@ fn filter_redundant_clues_with_rules_suppresses_ignorable_rule_and_cross_clues()
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(42),
@@ -171,28 +171,28 @@ fn filter_redundant_clues_with_rules_suppresses_ignorable_rule_and_cross_clues()
     }];
     files[0].copyrights = vec![Copyright {
         copyright: "Copyright Example Corp".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].holders = vec![crate::models::Holder {
         holder: "Example Corp".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].authors = vec![Author {
         author: "Jane Example".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].emails = vec![OutputEmail {
         email: "legal@example.com".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].urls = vec![OutputURL {
         url: "https://example.com/".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
 
     let clue_rule_lookup = HashMap::from([(
@@ -225,8 +225,8 @@ fn filter_redundant_clues_with_rules_keeps_non_exact_ignorable_values() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(42),
@@ -243,8 +243,8 @@ fn filter_redundant_clues_with_rules_keeps_non_exact_ignorable_values() {
     }];
     files[0].holders = vec![crate::models::Holder {
         holder: "Example Corp".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
 
     let clue_rule_lookup = HashMap::from([(
@@ -266,28 +266,28 @@ fn filter_redundant_clues_suppresses_cross_clues_without_license_rules() {
     let mut files = vec![file("project/a.txt")];
     files[0].copyrights = vec![Copyright {
         copyright: "Copyright Example <legal@example.com> https://example.com".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].holders = vec![crate::models::Holder {
         holder: "Jane Example".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].authors = vec![Author {
         author: "Jane Example".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].emails = vec![OutputEmail {
         email: "legal@example.com".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].urls = vec![OutputURL {
         url: "https://example.com/".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
 
     filter_redundant_clues(&mut files);
@@ -310,8 +310,8 @@ fn filter_redundant_clues_with_rules_uses_package_origin_detections() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/package.json".to_string()),
-                start_line: 1,
-                end_line: 5,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(5).unwrap(),
                 matcher: Some("parser-declared-license".to_string()),
                 score: 100.0,
                 matched_length: Some(42),
@@ -330,13 +330,13 @@ fn filter_redundant_clues_with_rules_uses_package_origin_detections() {
     }];
     files[0].emails = vec![OutputEmail {
         email: "legal@example.com".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
     files[0].urls = vec![OutputURL {
         url: "https://example.com/".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
 
     let clue_rule_lookup = HashMap::from([(
@@ -364,8 +364,8 @@ fn filter_redundant_clues_with_rules_ignores_low_coverage_matches() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: None,
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(42),
@@ -382,8 +382,8 @@ fn filter_redundant_clues_with_rules_ignores_low_coverage_matches() {
     }];
     files[0].emails = vec![OutputEmail {
         email: "legal@example.com".to_string(),
-        start_line: 2,
-        end_line: 2,
+        start_line: LineNumber::new(2).unwrap(),
+        end_line: LineNumber::new(2).unwrap(),
     }];
 
     let clue_rule_lookup = HashMap::from([(
@@ -411,14 +411,14 @@ fn ignore_resource_filter_removes_matching_files_and_preserves_needed_dirs() {
     ];
     files[3].authors = vec![Author {
         author: "Jane Doe".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     files[3].license_expression = Some("mit".to_string());
     files[4].holders = vec![crate::models::Holder {
         holder: "Example Corp".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     files[4].scan_errors = vec!["should still be dropped".to_string()];
 
@@ -504,8 +504,8 @@ fn normalize_paths_updates_license_match_from_file_paths_too() {
         license_expression: "mit".to_string(),
         license_expression_spdx: "MIT".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 1,
-        end_line: 2,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 100.0,
         matched_length: Some(12),
@@ -524,8 +524,8 @@ fn normalize_paths_updates_license_match_from_file_paths_too() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("project/LICENSE".to_string()),
-            start_line: 1,
-            end_line: 5,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::new(5).unwrap(),
             matcher: Some("2-aho".to_string()),
             score: 100.0,
             matched_length: Some(42),
@@ -567,8 +567,8 @@ fn normalize_paths_updates_package_level_license_match_from_file_paths_too() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("project/LICENSE".to_string()),
-                start_line: 1,
-                end_line: 5,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(5).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(42),
@@ -590,8 +590,8 @@ fn normalize_paths_updates_package_level_license_match_from_file_paths_too() {
                 license_expression: "apache-2.0".to_string(),
                 license_expression_spdx: "Apache-2.0".to_string(),
                 from_file: Some("project/NOTICE".to_string()),
-                start_line: 1,
-                end_line: 3,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::new(3).unwrap(),
                 matcher: Some("2-aho".to_string()),
                 score: 100.0,
                 matched_length: Some(30),
@@ -665,8 +665,8 @@ fn only_findings_keeps_clue_only_files() {
         license_expression: "unknown-license-reference".to_string(),
         license_expression_spdx: "LicenseRef-scancode-unknown-license-reference".to_string(),
         from_file: Some("project/NOTICE".to_string()),
-        start_line: 1,
-        end_line: 2,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::new(2).unwrap(),
         matcher: Some("2-aho".to_string()),
         score: 100.0,
         matched_length: Some(19),
diff --git a/src/scan_result_shaping/json_input_test.rs b/src/scan_result_shaping/json_input_test.rs
index dbee14e94..5d518f46d 100644
--- a/src/scan_result_shaping/json_input_test.rs
+++ b/src/scan_result_shaping/json_input_test.rs
@@ -1,4 +1,5 @@
 use super::*;
+use crate::models::LineNumber;
 use crate::scan_result_shaping::test_fixtures::json_file;
 use serde_json::json;
 use std::fs;
@@ -88,8 +89,8 @@ fn normalize_loaded_json_scan_applies_strip_root_per_loaded_input() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("archive/root/src/main.rs".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: None,
                 score: 100.0,
                 matched_length: None,
@@ -145,8 +146,8 @@ fn normalize_loaded_json_scan_trims_full_root_display_without_absolutizing() {
                 license_expression: "mit".to_string(),
                 license_expression_spdx: "MIT".to_string(),
                 from_file: Some("/tmp/archive/root/src/main.rs".to_string()),
-                start_line: 1,
-                end_line: 1,
+                start_line: LineNumber::ONE,
+                end_line: LineNumber::ONE,
                 matcher: None,
                 score: 100.0,
                 matched_length: None,
diff --git a/src/scan_result_shaping/mod.rs b/src/scan_result_shaping/mod.rs
index d9698ec02..0cbb5450a 100644
--- a/src/scan_result_shaping/mod.rs
+++ b/src/scan_result_shaping/mod.rs
@@ -12,7 +12,7 @@ use std::path::{Path, PathBuf};
 
 use crate::license_detection::LicenseDetectionEngine;
 use crate::license_detection::index::LicenseIndex;
-use crate::models::{FileInfo, Match, Package, TopLevelDependency};
+use crate::models::{FileInfo, LineNumber, Match, Package, TopLevelDependency};
 use anyhow::Result;
 
 pub(crate) use json_input::load_and_merge_json_inputs;
@@ -120,8 +120,8 @@ pub(crate) type ClueRuleLookup = HashMap<String, ClueRuleData>;
 
 #[derive(Debug, Clone)]
 struct IgnorableSpan {
-    start_line: usize,
-    end_line: usize,
+    start_line: LineNumber,
+    end_line: LineNumber,
     values: Vec<String>,
     allow_substring: bool,
 }
@@ -396,8 +396,8 @@ fn collect_rule_ignorables(
 
 fn push_ignorable_values(
     target: &mut Vec<IgnorableSpan>,
-    start_line: usize,
-    end_line: usize,
+    start_line: LineNumber,
+    end_line: LineNumber,
     values: &[String],
     trim_slashes: bool,
 ) {
@@ -419,8 +419,8 @@ fn push_ignorable_values(
 
 fn matches_ignorable(
     ignorables: &[IgnorableSpan],
-    start_line: usize,
-    end_line: usize,
+    start_line: LineNumber,
+    end_line: LineNumber,
     value: &str,
     trim_slashes: bool,
 ) -> bool {
diff --git a/src/scanner/mod.rs b/src/scanner/mod.rs
index 545f945c9..4bbb04e6d 100644
--- a/src/scanner/mod.rs
+++ b/src/scanner/mod.rs
@@ -245,7 +245,7 @@ mod tests {
         let emails: Vec<(&str, usize)> = scanned
             .emails
             .iter()
-            .map(|email| (email.email.as_str(), email.start_line))
+            .map(|email| (email.email.as_str(), email.start_line.get()))
             .collect();
 
         assert_eq!(emails.len(), 4, "emails: {emails:#?}");
@@ -426,7 +426,13 @@ mod tests {
         let authors: Vec<(&str, usize, usize)> = scanned
             .authors
             .iter()
-            .map(|author| (author.author.as_str(), author.start_line, author.end_line))
+            .map(|author| {
+                (
+                    author.author.as_str(),
+                    author.start_line.get(),
+                    author.end_line.get(),
+                )
+            })
             .collect();
 
         assert_eq!(
diff --git a/src/scanner/process.rs b/src/scanner/process.rs
index b73a239c3..f4ae20dd1 100644
--- a/src/scanner/process.rs
+++ b/src/scanner/process.rs
@@ -26,7 +26,7 @@ use crate::license_detection::models::LicenseMatch as InternalLicenseMatch;
 use crate::license_detection::query::Query;
 use crate::models::{
     Author, Copyright, DatasourceId, FileInfo, FileInfoBuilder, FileType, Holder, LicenseDetection,
-    Match, OutputEmail, OutputURL, Sha256Digest,
+    LineNumber, Match, OutputEmail, OutputURL, Sha256Digest,
 };
 use crate::parsers::utils::split_name_email;
 use crate::progress::ScanProgress;
@@ -687,7 +687,12 @@ fn prune_binary_string_detections(
     (kept_copyrights, kept_holders, kept_authors)
 }
 
-fn ranges_overlap(a_start: usize, a_end: usize, b_start: usize, b_end: usize) -> bool {
+fn ranges_overlap(
+    a_start: LineNumber,
+    a_end: LineNumber,
+    b_start: LineNumber,
+    b_end: LineNumber,
+) -> bool {
     a_start <= b_end && b_start <= a_end
 }
 
@@ -739,8 +744,8 @@ fn extract_binary_string_author_supplements(text_content: &str) -> Vec<AuthorDet
         if let Some(author) = extract_named_author_from_binary_line(line) {
             authors.push(AuthorDetection {
                 author,
-                start_line: line_index + 1,
-                end_line: line_index + 1,
+                start_line: LineNumber::from_0_indexed(line_index),
+                end_line: LineNumber::from_0_indexed(line_index),
             });
         }
     }
@@ -1234,8 +1239,8 @@ fn convert_match_to_model(
         m.matched_text.clone().or_else(|| {
             Some(crate::license_detection::query::matched_text_from_text(
                 text_content,
-                m.start_line,
-                m.end_line,
+                m.start_line.get(),
+                m.end_line.get(),
             ))
         })
     } else {
@@ -1292,15 +1297,15 @@ fn matched_text_diagnostics_from_match(
     let Some(start_pos) = matched_positions.iter().min() else {
         return crate::license_detection::query::matched_text_from_text(
             &query.text,
-            license_match.start_line,
-            license_match.end_line,
+            license_match.start_line.get(),
+            license_match.end_line.get(),
         );
     };
     let Some(end_pos) = matched_positions.iter().max() else {
         return crate::license_detection::query::matched_text_from_text(
             &query.text,
-            license_match.start_line,
-            license_match.end_line,
+            license_match.start_line.get(),
+            license_match.end_line.get(),
         );
     };
 
@@ -1310,8 +1315,8 @@ fn matched_text_diagnostics_from_match(
         &matched_positions,
         start_pos,
         end_pos,
-        license_match.start_line,
-        license_match.end_line,
+        license_match.start_line.get(),
+        license_match.end_line.get(),
     )
 }
 
@@ -1447,14 +1452,16 @@ mod tests {
 
     use super::maybe_record_processing_timeout;
 
+    use crate::models::LineNumber;
+
     fn make_internal_match(rule_url: &str) -> LicenseMatch {
         LicenseMatch {
             rid: 0,
             license_expression: "mit".to_string(),
             license_expression_spdx: Some("MIT".to_string()),
             from_file: None,
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             start_token: 0,
             end_token: 1,
             matcher: MatcherKind::Hash,
@@ -1659,8 +1666,8 @@ mod tests {
         detection.matches[0].license_expression_spdx = Some("FSFAP".to_string());
         detection.matches[0].rule_identifier = "fsf-ap.LICENSE".to_string();
         detection.matches[0].matched_text = None;
-        detection.matches[0].start_line = 1;
-        detection.matches[0].end_line = 3;
+        detection.matches[0].start_line = LineNumber::ONE;
+        detection.matches[0].end_line = LineNumber::new(3).unwrap();
         detection.matches[0].start_token = 0;
         detection.matches[0].end_token = query.tokens.len();
         detection.matches[0].coordinates =
diff --git a/tests/output_format_golden.rs b/tests/output_format_golden.rs
index 63905d9d7..b2e53cf42 100644
--- a/tests/output_format_golden.rs
+++ b/tests/output_format_golden.rs
@@ -1,7 +1,7 @@
 use provenant::models::{
     Copyright, DatasourceId, ExtraData, FacetTallies, FileInfo, FileType, Header, Holder,
-    Md5Digest, Output, Package, PackageData, PackageType, Party, ResolvedPackage, Sha1Digest,
-    SystemEnvironment, Tallies, TallyEntry, TopLevelDependency,
+    LineNumber, Md5Digest, Output, Package, PackageData, PackageType, Party, ResolvedPackage,
+    Sha1Digest, SystemEnvironment, Tallies, TallyEntry, TopLevelDependency,
 };
 use provenant::{OutputFormat, OutputWriteConfig, OutputWriter, writer_for_format};
 use regex::Regex;
@@ -107,8 +107,8 @@ fn test_debian_output_matches_local_expected_fixture() {
     );
     file.holders = vec![Holder {
         holder: "Example Org".to_string(),
-        start_line: 1,
-        end_line: 1,
+        start_line: LineNumber::ONE,
+        end_line: LineNumber::ONE,
     }];
     file.license_expression = Some("MIT".to_string());
     file.license_detections = vec![provenant::models::LicenseDetection {
@@ -118,8 +118,8 @@ fn test_debian_output_matches_local_expected_fixture() {
             license_expression: "mit".to_string(),
             license_expression_spdx: "MIT".to_string(),
             from_file: Some("scan/src/main.rs".to_string()),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
             matcher: Some("1-hash".to_string()),
             score: 100.0,
             matched_length: Some(1),
@@ -1600,13 +1600,13 @@ fn sample_html_simple_output() -> Output {
         vec![],
         vec![Copyright {
             copyright: "Copyright (c) 2000 ACME, Inc.".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         }],
         vec![Holder {
             holder: "ACME, Inc.".to_string(),
-            start_line: 1,
-            end_line: 1,
+            start_line: LineNumber::ONE,
+            end_line: LineNumber::ONE,
         }],
         vec![],
         vec![],
diff --git a/tests/scanner_copyright_credits.rs b/tests/scanner_copyright_credits.rs
index 7609ecfed..2f3d1d7f9 100644
--- a/tests/scanner_copyright_credits.rs
+++ b/tests/scanner_copyright_credits.rs
@@ -68,8 +68,8 @@ fn scanner_matches_structured_credits_fixture() {
         .into_iter()
         .map(|author| ExpectedAuthor {
             author: author.author,
-            start_line: author.start_line,
-            end_line: author.end_line,
+            start_line: author.start_line.get(),
+            end_line: author.end_line.get(),
         })
         .collect();
 
diff --git a/tests/scanner_integration.rs b/tests/scanner_integration.rs
index 9f1dfd276..7c3e992a4 100644
--- a/tests/scanner_integration.rs
+++ b/tests/scanner_integration.rs
@@ -1,7 +1,7 @@
 use glob::Pattern;
 use once_cell::sync::Lazy;
 use provenant::license_detection::LicenseDetectionEngine;
-use provenant::models::PackageType;
+use provenant::models::{LineNumber, PackageType};
 use provenant::parsers::list_parser_types;
 use provenant::progress::{ProgressMode, ScanProgress};
 use provenant::scanner::LicenseScanOptions;
@@ -577,13 +577,13 @@ fn test_scanner_detects_emails_and_urls_when_enabled() {
 
     assert_eq!(file.emails.len(), 1);
     assert_eq!(file.emails[0].email, "support@many.org");
-    assert_eq!(file.emails[0].start_line, 1);
-    assert_eq!(file.emails[0].end_line, 1);
+    assert_eq!(file.emails[0].start_line, LineNumber::ONE);
+    assert_eq!(file.emails[0].end_line, LineNumber::ONE);
 
     assert_eq!(file.urls.len(), 1);
     assert_eq!(file.urls[0].url, "http://www.acme.dev/docs");
-    assert_eq!(file.urls[0].start_line, 2);
-    assert_eq!(file.urls[0].end_line, 2);
+    assert_eq!(file.urls[0].start_line, LineNumber::new(2).unwrap());
+    assert_eq!(file.urls[0].end_line, LineNumber::new(2).unwrap());
 }
 
 #[test]
@@ -626,13 +626,13 @@ fn test_scanner_detects_copyrights_in_latin1_text() {
         file.copyrights[0].copyright,
         "Copyright 2024 François Müller"
     );
-    assert_eq!(file.copyrights[0].start_line, 1);
-    assert_eq!(file.copyrights[0].end_line, 1);
+    assert_eq!(file.copyrights[0].start_line, LineNumber::ONE);
+    assert_eq!(file.copyrights[0].end_line, LineNumber::ONE);
 
     assert_eq!(file.holders.len(), 1);
     assert_eq!(file.holders[0].holder, "François Müller");
-    assert_eq!(file.holders[0].start_line, 1);
-    assert_eq!(file.holders[0].end_line, 1);
+    assert_eq!(file.holders[0].start_line, LineNumber::ONE);
+    assert_eq!(file.holders[0].end_line, LineNumber::ONE);
 }
 
 #[test]