diff --git a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
index 5709feb..a0f6881 100644
--- a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -93,7 +93,11 @@ public function diff($config_file) {
     );
 
     $output['diff'] = array(
-      '#markup' => theme('table', $variables),
+      '#markup' => drupal_render(array(
+	    '#theme' => 'table',
+	    '#header' => $variables['header'],
+	    '#rows' => $variables['rows'],
+	  ),
     );
 
     $output['back'] = array(