diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
@@ -336,8 +336,7 @@
     $category = $this->database->query('SELECT cid, title FROM {aggregator_category} WHERE cid = :cid', array(':cid' => $cid))->fetchObject();
     drupal_set_title($category->title);
 
-    // @todo move included functions to controller.
-    module_load_include('inc', 'aggregator', 'aggregator.pages');
+    $this->moduleHandler->loadInclude('aggregator', 'inc', 'aggregator.pages');
 
     return aggregator_page_category($category);
   }