diff --git a/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php b/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
index c608b87..7a5f75a 100644
--- a/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
+++ b/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
@@ -153,15 +153,20 @@ public function checkNodeAccess(array $tree) {
    * Load all entities which are part of the menu tree using loadMultiple().
    *
    * @param \Drupal\Core\Menu\MenuLinkTreeElement[] $tree
-   *   The menu link tree to manipulate.
+   *   The menu link tree.
+   *
+   * @return \Drupal\Core\Menu\MenuLinkTreeElement[] $tree
+   *   The unmanipulated menu link tree.
    */
-  public function loadEntities(array &$tree) {
+  public function loadEntities(array $tree) {
     $entity_ids = [];
     $this->collectEntityIds($tree, $entity_ids);
 
     foreach ($entity_ids as $entity_type => $ids) {
       $this->entityManager->getStorage($entity_type)->loadMultiple(array_unique($ids));
     }
+
+    return $tree;
   }
 
   /**
diff --git a/core/modules/menu_ui/src/Tests/MenuNodeTest.php b/core/modules/menu_ui/src/Tests/MenuNodeTest.php
index ed8ff07..6434a17 100644
--- a/core/modules/menu_ui/src/Tests/MenuNodeTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuNodeTest.php
@@ -10,7 +10,6 @@
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\simpletest\WebTestBase;
-use Drupal\menu_link_content\Entity\MenuLinkContent;
 
 /**
  * Add, edit, and delete a node with menu link.