diff --git a/core/modules/taxonomy/src/Entity/Vocabulary.php b/core/modules/taxonomy/src/Entity/Vocabulary.php
index f793ae9..83ea6ca 100644
--- a/core/modules/taxonomy/src/Entity/Vocabulary.php
+++ b/core/modules/taxonomy/src/Entity/Vocabulary.php
@@ -116,12 +116,14 @@ public function postSave(EntityStorageInterface $storage, $update = TRUE) {
       foreach ($field_storages as $field_storage) {
         $update_storage = FALSE;
 
-        foreach ($field_storage->getSetting('allowed_values') as &$value) {
+        $allowed_values = $field_storage->getSetting('allowed_values');
+        foreach ($allowed_values as &$value) {
           if ($value['vocabulary'] == $this->getOriginalId()) {
             $value['vocabulary'] = $this->id();
             $update_storage = TRUE;
           }
         }
+        $field_storage->setSetting('allowed_values', $allowed_values);
 
         if ($update_storage) {
           $field_storage->save();