diff --git a/core/modules/comment/src/Controller/CommentController.php b/core/modules/comment/src/Controller/CommentController.php
index add5333..341d9c2 100644
--- a/core/modules/comment/src/Controller/CommentController.php
+++ b/core/modules/comment/src/Controller/CommentController.php
@@ -87,10 +87,15 @@ public static function create(ContainerInterface $container) {
    *   Redirects to the permalink URL for this comment.
    */
   public function commentApprove(CommentInterface $comment) {
-    $comment->setPublished(TRUE);
-    $comment->save();
+    if ($comment->isPublished()) {
+      drupal_set_message($this->t('The comment is already published.'));
+    }
+    else {
+      $comment->setPublished(TRUE);
+      $comment->save();
+      drupal_set_message($this->t('Comment approved.'));
+    }
 
-    drupal_set_message($this->t('Comment approved.'));
     $permalink_uri = $comment->permalink();
     $permalink_uri->setAbsolute();
     return new RedirectResponse($permalink_uri->toString());