diff --git a/core/modules/aggregator/aggregator.services.yml b/core/modules/aggregator/aggregator.services.yml
index 2296922..c2828c9 100644
--- a/core/modules/aggregator/aggregator.services.yml
+++ b/core/modules/aggregator/aggregator.services.yml
@@ -15,4 +15,4 @@ services:
       - { name: access_check }
   aggregator.category.storage:
     class: Drupal\aggregator\CategoryStorageController
-    arguments: ['@database', '@plugin.manager.entity', '@module_handler']
+    arguments: ['@database']
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageController.php b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageController.php
index 77e978d..299113c 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageController.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageController.php
@@ -22,6 +22,13 @@ class CategoryStorageController implements CategoryStorageControllerInterface {
   protected $database;
 
   /**
+   * A cache of loaded categories.
+   *
+   * @var \stdClass[]
+   */
+  protected $categories;
+
+  /**
    * Creates a new CategoryStorageController object.
    *
    * @param \Drupal\Core\Database\Connection $database
@@ -35,17 +42,20 @@ public function __construct(Connection $database) {
    * {@inheritdoc}
    */
   public function load($cid) {
-    return $this->database->query("SELECT * FROM {aggregator_category} WHERE cid = :cid", array(':cid' => $cid))->fetchObject();
+    if (!isset($this->categories[$cid])) {
+      $this->categories[$cid] = $this->database->query("SELECT * FROM {aggregator_category} WHERE cid = :cid", array(':cid' => $cid))->fetchObject();
+    }
+    return $this->categories[$cid];
   }
 
   /**
    * {@inheritdoc}
    */
-  public function save(array $category) {
+  public function save($category) {
     $cid = $this->database->insert('aggregator_category')
       ->fields(array(
-        'title' => $category['title'],
-        'description' => $category['description'],
+        'title' => $category->title,
+        'description' => $category->description,
         'block' => 5,
       ))
       ->execute();
@@ -55,12 +65,12 @@ public function save(array $category) {
   /**
    * {@inheritdoc}
    */
-  public function update(array $category) {
+  public function update($category) {
     $this->database->merge('aggregator_category')
-      ->key(array('cid' => $category['cid']))
+      ->key(array('cid' => $category->cid))
       ->fields(array(
-        'title' => $category['title'],
-        'description' => $category['description'],
+        'title' => $category->title,
+        'description' => $category->description,
       ))
       ->execute();
   }
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
index c3e9e0a..a4ab4db 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/CategoryStorageControllerInterface.php
@@ -19,28 +19,28 @@
    *   The unique category ID.
    *
    * @return stdClass|null
-   *   An array of category properties.
+   *   An object containing all category properties.
    */
   public function load($cid);
 
   /**
    * Saves an aggregator category.
    *
-   * @param array $category
+   * @param \stdClass $category
    *   The category to save.
    *
    * @return int
    *   The new category ID.
    */
-  public function save(array $category);
+  public function save($category);
 
   /**
    * Updates and aggregator category.
    *
-   * @param array $category
+   * @param \stdClass $category
    *   The category.
    */
-  public function update(array $category);
+  public function update($category);
 
   /**
    * Deletes an aggregator category.
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryAdminForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryAdminForm.php
index 219e17f..987dc1e 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryAdminForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryAdminForm.php
@@ -174,7 +174,7 @@ public function submitForm(array &$form, array &$form_state) {
     // Update the category.
     if (!empty($form_state['values']['cid'])) {
       $cid = $form_state['values']['cid'];
-      $this->categoryStorageController->update($form_state['values']);
+      $this->categoryStorageController->update((object) $form_state['values']);
       drupal_set_message(t('The category %category has been updated.', array('%category' => $title)));
       if (preg_match('/^\/admin/', $this->request->getPathInfo())) {
         $form_state['redirect'] = 'admin/config/services/aggregator/';
@@ -187,7 +187,7 @@ public function submitForm(array &$form, array &$form_state) {
     }
 
     // Insert the category.
-    $cid = $this->categoryStorageController->save($form_state['values']);
+    $cid = $this->categoryStorageController->save((object) $form_state['values']);
     watchdog('aggregator', 'Category %category added.', array('%category' => $form_state['values']['title']), WATCHDOG_NOTICE, l(t('view'), 'admin/config/services/aggregator'));
     drupal_set_message(t('The category %category has been added.', array('%category' => $title)));
 
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryDeleteForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryDeleteForm.php
index c057bd1..038e3cc 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryDeleteForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/CategoryDeleteForm.php
@@ -51,7 +51,9 @@ class CategoryDeleteForm extends ConfirmFormBase implements ControllerInterface
   protected $categoryStorageController;
 
   /**
-   * @var
+   * The current request.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
    */
   protected $request;