diff --git a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
index 477268c..d9518b6 100644
--- a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -77,8 +77,14 @@ public function diff($config_file) {
       'rows' => $formatter->format($diff),
     );
 
+    $table = array(
+      '#theme' => 'table',   
+      '#header' => $variables['header'],
+      '#rows' => $variables['rows']
+    );
+    
     $output['diff'] = array(
-      '#markup' => theme('table', $variables),
+      '#markup' => drupal_render($table),
     );
 
     $output['back'] = array(