diff --git a/src/Controller/ThreadController.php b/src/Controller/ThreadController.php
index 45bc82fbf..97ed9daa9 100644
--- a/src/Controller/ThreadController.php
+++ b/src/Controller/ThreadController.php
@@ -542,7 +542,7 @@ protected function onCreateCommentError(FormInterface $form, string $id, Comment
             ->setStatusCode(Response::HTTP_BAD_REQUEST)
             ->setData([
                     'data' => [
-                        'form' => $form,
+                        'form' => $form->createView(),
                         'id' => $id,
                         'parent' => $parent,
                     ],