diff --git a/core/modules/comment/lib/Drupal/comment/CommentFormController.php b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
index 1599365..985f900 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentFormController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
@@ -63,9 +63,11 @@ public function form(array $form, array &$form_state) {
       $author = $comment->name->value;
       $status = (isset($comment->status->value) ? $comment->status->value : COMMENT_NOT_PUBLISHED);
       $date = (!empty($comment->date) ? $comment->date : DrupalDateTime::createFromTimestamp($comment->created->value));
-      $form['#title'] = t('Edit comment %title', array(
-        '%title' => $comment->subject->value,
-      ));
+      if (empty($form_state['comment_preview'])) {
+        $form['#title'] = t('Edit comment %title', array(
+          '%title' => $comment->subject->value,
+        ));
+      }
     }
     else {
       if ($user->isAuthenticated()) {