diff --git a/core/modules/comment/lib/Drupal/comment/CommentFormController.php b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
index e2f4286..750f748 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentFormController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
@@ -306,6 +306,7 @@ public function submit(array $form, array &$form_state) {
    */
   public function preview(array $form, array &$form_state) {
     $comment = $this->entity;
+    drupal_set_title(t('Preview comment'), PASS_THROUGH);
     $form_state['comment_preview'] = comment_preview($comment);
     $form_state['rebuild'] = TRUE;
   }