diff --git a/core/lib/Drupal/Core/Config/ConfigManager.php b/core/lib/Drupal/Core/Config/ConfigManager.php
index 65a7846..1816d04 100644
--- a/core/lib/Drupal/Core/Config/ConfigManager.php
+++ b/core/lib/Drupal/Core/Config/ConfigManager.php
@@ -50,6 +50,12 @@ class ConfigManager implements ConfigManagerInterface {
    *
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The configuration factory.
+   * @param \Drupal\Core\Config\TypedConfigManager $typed_config_manager
+   *   The typed config manager.
+   * @param \Drupal\Core\StringTranslation\TranslationManager $string_translation
+   *   he string translation service.
    */
   public function __construct(EntityManagerInterface $entity_manager, ConfigFactoryInterface $config_factory, TypedConfigManager $typed_config_manager, TranslationManager $string_translation) {
     $this->entityManager = $entity_manager;
@@ -80,8 +86,8 @@ public function getEntityManager() {
    */
   public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $name) {
     // @todo Replace with code that can be autoloaded.
-    //   https://drupal.org/node/2188595
-    require_once DRUPAL_ROOT . '/core/lib/Drupal/Component/Diff/DiffEngine.php';
+    //   https://drupal.org/node/1848266
+    require_once __DIR__ . '/../../Component/Diff/DiffEngine.php';
 
     // The output should show configuration object differences formatted as YAML.
     // But the configuration is not necessarily stored in files. Therefore, they