diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ebc7464..5bc6ef28 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## Unreleased
 
+- Always use an `unsafe` block to `unsafe_main_ptr`. ([#643](https://github.com/fastly/Viceroy/pull/643))
+
 ## 0.19.0 (2026-06-16)
 
 - Fix adapter codegen to avoid memory shift overflow, and support SIMD instructions. ([#629](https://github.com/fastly/Viceroy/pull/629))
diff --git a/wasm_abi/adapter/src/macros.rs b/wasm_abi/adapter/src/macros.rs
index 2471dc60..496467e6 100644
--- a/wasm_abi/adapter/src/macros.rs
+++ b/wasm_abi/adapter/src/macros.rs
@@ -42,7 +42,10 @@ macro_rules! main_ptr {
 #[cfg(feature = "noshift")]
 macro_rules! unsafe_main_ptr {
     ($ptr:expr) => {{
-        $ptr
+        // Always wrap `$ptr` in `unsafe` for consistency with the
+        // `not(feature = "noshift")` version.
+        #[allow(unused_unsafe)]
+        unsafe { $ptr }
     }};
 }
 #[cfg(feature = "noshift")]
diff --git a/wasm_abi/data/viceroy-component-adapter.library.noshift.wasm b/wasm_abi/data/viceroy-component-adapter.library.noshift.wasm
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