diff --git a/src/optimization/dce.ml b/src/optimization/dce.ml
index 7da5e99d695..d1bb998a237 100644
--- a/src/optimization/dce.ml
+++ b/src/optimization/dce.ml
@@ -87,7 +87,7 @@ let overrides_extern_field cf c =
 	loop c cf
 
 let is_std_file dce file =
-	List.exists (ExtString.String.starts_with file) dce.std_dirs
+	List.exists (fun dir -> ExtString.String.starts_with file dir) dce.std_dirs
 
 let keep_metas = [Meta.Keep;Meta.Expose]