diff --git a/bytecomp/translcore.ml b/bytecomp/translcore.ml
index 0d2721d2c..bf810f32f 100644
--- a/bytecomp/translcore.ml
+++ b/bytecomp/translcore.ml
@@ -1170,7 +1170,8 @@ and transl_record env all_labels repres lbl_expr_list opt_init_expr =
       lbl_expr_list;
     let ll = Array.to_list lv in
     let mut =
-      if List.exists (fun (_, lbl, expr) -> lbl.lbl_mut = Mutable) lbl_expr_list
+      if List.exists (fun lbl -> lbl.lbl_mut = Mutable)
+        (Array.to_list all_labels)
       then Mutable
       else Immutable in
     let lam =