diff --git a/R/loadfast.R b/R/loadfast.R
index 5f9255f..02b606a 100644
--- a/R/loadfast.R
+++ b/R/loadfast.R
@@ -59,7 +59,7 @@ load_fast <- function(path = ".", helpers = TRUE, attach_testthat = NULL, full =
   desc_path <- file.path(abs_path, "DESCRIPTION")
   if (!file.exists(desc_path)) stop("DESCRIPTION file not found at: ", desc_path)
   desc_fields <- read.dcf(desc_path)
-  pkg_name <- if ("Package" %in% colnames(desc_fields)) trimws(desc_fields[1L, "Package"]) else ""
+  pkg_name <- if ("Package" %in% colnames(desc_fields)) unname(trimws(desc_fields[1L, "Package"])) else ""
   if (!nzchar(pkg_name)) stop("No valid 'Package' field found in DESCRIPTION")
 
   pkg_env_name <- paste0("package:", pkg_name)
@@ -257,6 +257,9 @@ load_fast <- function(path = ".", helpers = TRUE, attach_testthat = NULL, full =
   ns_env[[".__NAMESPACE__."]] <- info
   info[["spec"]] <- c(name = pkg_name, version = "0.0.0")
   setNamespaceInfo(ns_env, "exports", new.env(hash = TRUE, parent = baseenv()))
+  dimpenv <- new.env(parent = baseenv(), hash = TRUE)
+  attr(dimpenv, "name") <- paste0("lazydata:", pkg_name)
+  setNamespaceInfo(ns_env, "lazydata", dimpenv)
   setNamespaceInfo(ns_env, "imports", list(base = TRUE))
   setNamespaceInfo(ns_env, "path", abs_path)
   setNamespaceInfo(ns_env, "dynlibs", NULL)
diff --git a/test_loadfast.R b/test_loadfast.R
index 1b02b21..e427f1a 100644
--- a/test_loadfast.R
+++ b/test_loadfast.R
@@ -169,6 +169,14 @@ check("isNamespace() returns TRUE", quote(
   isNamespace(ns)
 ))
 
+check("lazydata env exists in namespace info", quote(
+  is.environment(ns[[".__NAMESPACE__."]][["lazydata"]])
+))
+
+check("lazydata env is named correctly", quote(
+  attr(ns[[".__NAMESPACE__."]][["lazydata"]], "name") == "lazydata:devpackage"
+))
+
 # --- Search path ---
 check("package:devpackage is on the search path", quote(
   "package:devpackage" %in% search()
@@ -1153,6 +1161,22 @@ check("same-name: second path is now the active namespace path", quote(
   )
 ))
 
+# --------------------------------------------------------------------------
+# 3f2: base::attachNamespace compatibility
+# --------------------------------------------------------------------------
+cat("\n--- 3f2: base::attachNamespace compatibility ---\n\n")
+
+tmp_attach <- tempfile("loadfast_attach_")
+copy_baseline(tmp_attach)
+rename_package(tmp_attach, "pkgattach")
+ns_attach <- load_fast(tmp_attach, helpers = FALSE, attach_testthat = FALSE)
+
+check("base::attachNamespace does not fail due to missing lazydata env", quote({
+  detach("package:pkgattach", unload = FALSE)
+  base::attachNamespace(ns_attach)
+  "package:pkgattach" %in% search()
+}))
+
 # --------------------------------------------------------------------------
 # 3g: Same-name different-path cache flip-flop and renv.lock path scoping
 # --------------------------------------------------------------------------