diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index b544908..dd844ab 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -176,10 +176,7 @@ function aggregator_menu() {
   $items['aggregator/categories/%aggregator_category'] = array(
     'title callback' => '_aggregator_category_title',
     'title arguments' => array(2),
-    'page callback' => 'aggregator_page_category',
-    'page arguments' => array(2),
-    'access arguments' => array('access news feeds'),
-    'file' => 'aggregator.pages.inc',
+    'route_name' => 'aggregator_category',
   );
   $items['aggregator/categories/%aggregator_category/view'] = array(
     'title' => 'View',
@@ -256,13 +253,15 @@ function aggregator_menu() {
 /**
  * Title callback: Returns a title for aggregator category pages.
  *
- * @param $category
- *   An aggregator category.
+ * @param int $cid
+ *   An aggregator category id.
  *
- * @return
+ * @return string
  *   A string with the aggregator category title.
  */
-function _aggregator_category_title($category) {
+function _aggregator_category_title($cid) {
+  // TODO category is not an entity so is not loaded automatically.
+  $category = db_query('SELECT cid, title FROM {aggregator_category} WHERE cid = :cid', array(':cid' => $cid))->fetchObject();
   return $category->title;
 }
 
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index 6248012..da7b71c 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -73,6 +73,9 @@ function aggregator_page_source_form($form, $form_state, $feed) {
  *
  * @see aggregator_menu()
  * @ingroup forms
+ *
+ * TODO Duplicates AggregatorController::category()
+ * remove this when no longer used by aggregator_page_category_form().
  */
 function aggregator_page_category($category) {
   drupal_add_feed('aggregator/rss/' . $category->cid, config('system.site')->get('name') . ' ' . t('aggregator - @title', array('@title' => $category->title)));
@@ -81,7 +84,7 @@ function aggregator_page_category($category) {
   // database by aggregator_category_load().
   $items = aggregator_load_feed_items('category', $category);
 
-  return _aggregator_page_list($items, arg(3));
+  return _aggregator_page_list($items, $category->cid);
 }
 
 /**
diff --git a/core/modules/aggregator/aggregator.routing.yml b/core/modules/aggregator/aggregator.routing.yml
index bf02d5c..715fa7c 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_category:
+  pattern: '/aggregator/categories/{cid}'
+  defaults:
+    _controller: '\Drupal\aggregator\Routing\AggregatorController::category'
+  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..315a4cc 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Routing/AggregatorController.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\aggregator\Routing;
 
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Database\Connection;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\ControllerInterface;
 use Drupal\Core\Entity\EntityManager;
@@ -24,20 +26,44 @@ class AggregatorController implements ControllerInterface {
   protected $entityManager;
 
   /**
+   * The config factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
+   * The database connection.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $database;
+
+  /**
    * Constructs a \Drupal\aggregator\Routing\AggregatorController object.
    *
    * @param \Drupal\Core\Entity\EntityManager $entity_manager
    *   The Entity manager.
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The config factory,
+   * @param \Drupal\Core\Database\Connection $database
+   *   The database connection.
    */
-  public function __construct(EntityManager $entity_manager) {
+  public function __construct(EntityManager $entity_manager, ConfigFactory $config_factory, Connection $database) {
     $this->entityManager = $entity_manager;
+    $this->configFactory = $config_factory;
+    $this->database = $database;
   }
 
   /**
    * {inheritdoc}
    */
   public static function create(ContainerInterface $container) {
-    return new static($container->get('plugin.manager.entity'));
+    return new static(
+      $container->get('plugin.manager.entity'),
+      $container->get('config.factory'),
+      $container->get('database')
+    );
   }
 
   /**
@@ -56,4 +82,29 @@ public function feedAdd() {
     return entity_get_form($feed);
   }
 
+  /**
+   * Form constructor to list items aggregated in a category.
+   *
+   * @param int $cid
+   *   The category id for which to list all of the aggregated items.
+   *
+   * @return string
+   *   The rendered list of items for the feed.
+   */
+  public function category($cid) {
+
+    $category = $this->database->query('SELECT cid, title FROM {aggregator_category} WHERE cid = :cid', array(':cid' => $cid))->fetchObject();
+
+    drupal_add_feed('aggregator/rss/' . $category->cid, $this->configFactory->get('system.site')->get('name') . ' ' . t('aggregator - @title', array('@title' => $category->title)));
+
+    // TODO move included functions to controller.
+    module_load_include('inc', 'aggregator', 'aggregator.pages');
+
+    // It is safe to include the cid in the query because it's loaded from the
+    // database by aggregator_category_load().
+    $items = aggregator_load_feed_items('category', $category);
+
+    return _aggregator_page_list($items, $cid);
+  }
+
 }