diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index b544908..e1bbaca 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -155,9 +155,7 @@ function aggregator_menu() {
   );
   $items['aggregator/categories'] = array(
     'title' => 'Categories',
-    'page callback' => 'aggregator_page_categories',
-    'access callback' => '_aggregator_has_categories',
-    'file' => 'aggregator.pages.inc',
+    'route_name' => 'aggregator_categories',
   );
   $items['aggregator/rss'] = array(
     'title' => 'RSS feed',
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index 6248012..9951b53 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -368,41 +368,6 @@ function aggregator_page_sources() {
 }
 
 /**
- * Page callback: Displays all the categories used by the Aggregator module.
- *
- * @return string
- *   An HTML formatted string.
- *
- * @see aggregator_menu()
- */
-function aggregator_page_categories() {
-  $result = db_query('SELECT c.cid, c.title, c.description FROM {aggregator_category} c LEFT JOIN {aggregator_category_item} ci ON c.cid = ci.cid LEFT JOIN {aggregator_item} i ON ci.iid = i.iid GROUP BY c.cid, c.title, c.description');
-
-  $build = array(
-    '#type' => 'container',
-    '#attributes' => array('class' => array('aggregator-wrapper')),
-    '#sorted' => TRUE,
-  );
-  $aggregator_summary_items = config('aggregator.settings')->get('source.list_max');
-  foreach ($result as $category) {
-    $summary_items = array();
-    if ($aggregator_summary_items) {
-      if ($items = aggregator_load_feed_items('category', $category, $aggregator_summary_items)) {
-        $summary_items = entity_view_multiple($items, 'summary');
-      }
-    }
-    $category->url = url('aggregator/categories/' . $category->cid);
-    $build[$category->cid] = array(
-      '#theme' => 'aggregator_summary_items',
-      '#summary_items' => $summary_items,
-      '#source' => $category,
-    );
-  }
-
-  return $build;
-}
-
-/**
  * Page callback: Generates an RSS 0.92 feed of aggregator items or categories.
  *
  * @return string
diff --git a/core/modules/aggregator/aggregator.routing.yml b/core/modules/aggregator/aggregator.routing.yml
index bf02d5c..d756689 100644
--- a/core/modules/aggregator/aggregator.routing.yml
+++ b/core/modules/aggregator/aggregator.routing.yml
@@ -25,3 +25,10 @@ aggregator_feed_add:
     _controller: '\Drupal\aggregator\Routing\AggregatorController::feedAdd'
   requirements:
     _permission: 'administer news feeds'
+
+aggregator_categories:
+  pattern: '/aggregator/categories'
+  defaults:
+    _controller: '\Drupal\aggregator\Routing\AggregatorController::categories'
+  requirements:
+    _permission: 'access news feeds'
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php b/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php
index 66f1fbd..aa94004 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php
@@ -56,4 +56,41 @@ public function feedAdd() {
     return entity_get_form($feed);
   }
 
+  /**
+   * Displays all the categories used by the Aggregator module.
+   *
+   * @return string
+   *   An HTML formatted string.
+   */
+  public function categories() {
+
+    // TODO move included functions to controller.
+    module_load_include('inc', 'aggregator', 'aggregator.pages');
+
+    $result = db_query('SELECT c.cid, c.title, c.description FROM {aggregator_category} c LEFT JOIN {aggregator_category_item} ci ON c.cid = ci.cid LEFT JOIN {aggregator_item} i ON ci.iid = i.iid GROUP BY c.cid, c.title, c.description');
+
+    $build = array(
+      '#type' => 'container',
+      '#attributes' => array('class' => array('aggregator-wrapper')),
+      '#sorted' => TRUE,
+    );
+    $aggregator_summary_items = config('aggregator.settings')->get('source.list_max');
+    foreach ($result as $category) {
+      $summary_items = array();
+      if ($aggregator_summary_items) {
+        if ($items = aggregator_load_feed_items('category', $category, $aggregator_summary_items)) {
+          $summary_items = entity_view_multiple($items, 'summary');
+        }
+      }
+      $category->url = url('aggregator/categories/' . $category->cid);
+      $build[$category->cid] = array(
+        '#theme' => 'aggregator_summary_items',
+        '#summary_items' => $summary_items,
+        '#source' => $category,
+      );
+    }
+
+    return $build;
+  }
+
 }