diff --git a/core/modules/editor/src/Entity/Editor.php b/core/modules/editor/src/Entity/Editor.php
index 9ddc0cb..38cfb52 100644
--- a/core/modules/editor/src/Entity/Editor.php
+++ b/core/modules/editor/src/Entity/Editor.php
@@ -82,7 +82,9 @@ public function __construct(array $values, $entity_type) {
     $plugin = $this->editorPluginManager()->createInstance($this->editor);
 
     /* @var \Drupal\editor\Plugin\EditorPluginInterface $plugin */
-    $this->settings = array_merge($this->settings, $plugin->getDefaultConfiguration());
+    if (is_array($plugin->getDefaultConfiguration())) {
+      $this->settings = array_merge($this->settings, $plugin->getDefaultConfiguration());
+    }
   }
 
   /**