diff --git a/tests/lean/rewrite.lean.expected.out b/tests/lean/rewrite.lean.expected.out
index 5d1a74f673..cace9e200b 100644
--- a/tests/lean/rewrite.lean.expected.out
+++ b/tests/lean/rewrite.lean.expected.out
@@ -2,6 +2,7 @@
 as bs : List α
 ⊢ as ++ bs ++ bs = as ++ (bs ++ bs)
 rewrite.lean:14:20: error: tactic 'rewrite' failed, did not find instance of the pattern in the target expression
+  List.reverse (List.reverse ?m)
 α : Type _
 as bs : List α
 ⊢ as ++ List.nil ++ List.nil ++ bs ++ bs = as ++ (bs ++ bs)