diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/VocabularyStorageController.php b/core/modules/taxonomy/lib/Drupal/taxonomy/VocabularyStorageController.php
index 62f6040..be8de64 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/VocabularyStorageController.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/VocabularyStorageController.php
@@ -124,7 +124,7 @@ public function resetCache(array $ids = NULL) {
    * @return
    *   An integer that represents the level of the vocabulary's hierarchy.
    */
-  public function checkHierarchy(VocabularyInterface $vocabulary, $changed_term) {
+  public function checkHierarchy(VocabularyInterface $vocabulary, array $changed_term) {
     $tree = taxonomy_get_tree($vocabulary->id());
     $hierarchy = TAXONOMY_HIERARCHY_DISABLED;
     foreach ($tree as $term) {