diff -u b/core/modules/config/src/Form/ConfigSync.php b/core/modules/config/src/Form/ConfigSync.php
--- b/core/modules/config/src/Form/ConfigSync.php
+++ b/core/modules/config/src/Form/ConfigSync.php
@@ -179,7 +179,7 @@
       }
       sort($change_list);
       $change_list_text = implode(', ', $change_list);
-      drupal_set_message($this->t('Your current configuration has changed. Changes to these configuration items will be lost on the next synchronization: ' . $change_list_text), 'warning');
+      drupal_set_message($this->t('Your current configuration has changed. Changes to these configuration items will be lost on the next synchronization: @changes', array('@changes' => $change_list_text)), 'warning');
     }
     $form['actions'] = array('#type' => 'actions');
     $form['actions']['submit'] = array(