diff --git a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
index b726965..90fb48f 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
@@ -69,11 +69,11 @@ public function isUnique($title, $cid = NULL);
   /**
    * Loads aggregator categories for an aggregator item.
    *
-   * @param array $item_id
+   * @param int $item_id
    *   The aggregator item ID.
    *
    * @return array
-   *   An array of
+   *   An array of objects containing item ID, category ID and title.
    */
   public function loadByItem($item_id);