diff --git a/selfhost/cmd/w6c/main.combined.ww b/selfhost/cmd/w6c/main.combined.ww
index 1cc8dd81..e9b5e468 100644
--- a/selfhost/cmd/w6c/main.combined.ww
+++ b/selfhost/cmd/w6c/main.combined.ww
@@ -14477,8 +14477,22 @@ fn checkletassign(c: *checker, n: *node) void = {
 	if (!ok) { if (assignableaddrfn(c, n.lhs, n.rhs)) { ok = true; }; };
 	if (!conf) { return; };
 	if (!ok) { errnotassign(c, n.lhs, src, "let"); };
-	// #258: `let s: []T = arr` borrows the array as a full slice.
-	n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	// #258: `let s: []T = arr` borrows the array as a full slice. The
+	// desugar lowers to a runtime `arr[0:len]` N_SLICE, so it only
+	// applies to LOCAL lets (a fn body executes the borrow). A MODULE-
+	// level let is static data with no runtime to run the borrow — its
+	// rhs must stay the raw N_ARRLIT so cgen can materialize it as DATA
+	// (#18). cstage splits this by checker: clet (the desugar site,
+	// cmd/wcc/check.c:1993) runs only from cstmt (local), while module-
+	// level lets are checked in check_file pass-2 (check.c:2549) which
+	// never desugars. wwstage runs ONE checkletassign for both (pass-2
+	// @checkfile + resolvewalk post-order), so mirror cstage's split
+	// here: skip at module scope (c.cur == c.top, the same module-scope
+	// test as L184). Keeps the #130 module-level assignability check
+	// above intact.
+	if (c.cur != c.top) {
+		n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	};
 };
 
 fn checkretassign(c: *checker, n: *node) void = {
diff --git a/selfhost/cmd/wcc/check.ww b/selfhost/cmd/wcc/check.ww
index 93393efe..04241ea5 100644
--- a/selfhost/cmd/wcc/check.ww
+++ b/selfhost/cmd/wcc/check.ww
@@ -4110,8 +4110,22 @@ fn checkletassign(c: *checker, n: *node) void = {
 	if (!ok) { if (assignableaddrfn(c, n.lhs, n.rhs)) { ok = true; }; };
 	if (!conf) { return; };
 	if (!ok) { errnotassign(c, n.lhs, src, "let"); };
-	// #258: `let s: []T = arr` borrows the array as a full slice.
-	n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	// #258: `let s: []T = arr` borrows the array as a full slice. The
+	// desugar lowers to a runtime `arr[0:len]` N_SLICE, so it only
+	// applies to LOCAL lets (a fn body executes the borrow). A MODULE-
+	// level let is static data with no runtime to run the borrow — its
+	// rhs must stay the raw N_ARRLIT so cgen can materialize it as DATA
+	// (#18). cstage splits this by checker: clet (the desugar site,
+	// cmd/wcc/check.c:1993) runs only from cstmt (local), while module-
+	// level lets are checked in check_file pass-2 (check.c:2549) which
+	// never desugars. wwstage runs ONE checkletassign for both (pass-2
+	// @checkfile + resolvewalk post-order), so mirror cstage's split
+	// here: skip at module scope (c.cur == c.top, the same module-scope
+	// test as L184). Keeps the #130 module-level assignability check
+	// above intact.
+	if (c.cur != c.top) {
+		n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	};
 };
 
 fn checkretassign(c: *checker, n: *node) void = {
diff --git a/selfhost/cmd/wwdump/main.combined.ww b/selfhost/cmd/wwdump/main.combined.ww
index a861f708..8a02399c 100644
--- a/selfhost/cmd/wwdump/main.combined.ww
+++ b/selfhost/cmd/wwdump/main.combined.ww
@@ -14477,8 +14477,22 @@ fn checkletassign(c: *checker, n: *node) void = {
 	if (!ok) { if (assignableaddrfn(c, n.lhs, n.rhs)) { ok = true; }; };
 	if (!conf) { return; };
 	if (!ok) { errnotassign(c, n.lhs, src, "let"); };
-	// #258: `let s: []T = arr` borrows the array as a full slice.
-	n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	// #258: `let s: []T = arr` borrows the array as a full slice. The
+	// desugar lowers to a runtime `arr[0:len]` N_SLICE, so it only
+	// applies to LOCAL lets (a fn body executes the borrow). A MODULE-
+	// level let is static data with no runtime to run the borrow — its
+	// rhs must stay the raw N_ARRLIT so cgen can materialize it as DATA
+	// (#18). cstage splits this by checker: clet (the desugar site,
+	// cmd/wcc/check.c:1993) runs only from cstmt (local), while module-
+	// level lets are checked in check_file pass-2 (check.c:2549) which
+	// never desugars. wwstage runs ONE checkletassign for both (pass-2
+	// @checkfile + resolvewalk post-order), so mirror cstage's split
+	// here: skip at module scope (c.cur == c.top, the same module-scope
+	// test as L184). Keeps the #130 module-level assignability check
+	// above intact.
+	if (c.cur != c.top) {
+		n.rhs = desugararrayslice(c, n.lhs, src, n.rhs);
+	};
 };
 
 fn checkretassign(c: *checker, n: *node) void = {