diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
index d7f0233..4d67770 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
@@ -28,6 +28,13 @@ class SettingsForm extends SystemConfigFormBase {
   protected $configFactory;
 
   /**
+   * The string translation service.
+   *
+   * @var \Drupal\Core\StringTranslation\TranslationManager
+   */
+  protected $string_translation;
+
+  /**
    * The aggregator plugin managers.
    *
    * @var array