diff --git a/core/modules/comment/lib/Drupal/comment/CommentAccessController.php b/core/modules/comment/lib/Drupal/comment/CommentAccessController.php
index 35d92c3..da957d2 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentAccessController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentAccessController.php
@@ -36,6 +36,10 @@ public function createAccess(EntityInterface $entity, $langcode = LANGUAGE_DEFAU
    * Overrides \Drupal\Core\Entity\EntityAccessController::updateAccess().
    */
   public function updateAccess(EntityInterface $entity, $langcode = LANGUAGE_DEFAULT, User $account = NULL) {
+    // If no user is specified fill in the current one.
+    if (!isset($account)) {
+      $account = $GLOBALS['user'];
+    }
     return ($account->uid && $account->id() == $entity->uid && $entity->status == COMMENT_PUBLISHED && user_access('edit own comments', $account)) || user_access('administer comments', $account);
   }