diff --git a/core/modules/aggregator/src/Controller/AggregatorController.php b/core/modules/aggregator/src/Controller/AggregatorController.php
index 303b43c..fbb14f1 100644
--- a/core/modules/aggregator/src/Controller/AggregatorController.php
+++ b/core/modules/aggregator/src/Controller/AggregatorController.php
@@ -51,7 +51,7 @@ public static function create(ContainerInterface $container) {
    * Presents the aggregator feed creation form.
    *
    * @return array
-   *   A form array as expected by drupal_render().
+   *   A form array as expected by $renderer->render().
    */
   public function feedAdd() {
     $feed = $this->entityManager()->getStorage('aggregator_feed')
@@ -111,7 +111,7 @@ public function feedRefresh(FeedInterface $aggregator_feed) {
    * Displays the aggregator administration page.
    *
    * @return array
-   *   A render array as expected by drupal_render().
+   *   A render array as expected by $renderer->render().
    */
   public function adminOverview() {
     $entity_manager = $this->entityManager();
diff --git a/core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php b/core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php
index fcc2584..877399b 100644
--- a/core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php
+++ b/core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Entity\Query\QueryInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Session\AccountInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -51,6 +52,13 @@ class AggregatorFeedBlock extends BlockBase implements ContainerFactoryPluginInt
   protected $itemQuery;
 
   /**
+   * The renderer service.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
    * Constructs an AggregatorFeedBlock object.
    *
    * @param array $configuration
@@ -65,12 +73,15 @@ class AggregatorFeedBlock extends BlockBase implements ContainerFactoryPluginInt
    *   The entity storage for feed items.
    * @param \Drupal\Core\Entity\Query\QueryInterface $item_query
    *   The entity query object for feed items.
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *   The renderer service.
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, FeedStorageInterface $feed_storage, ItemStorageInterface $item_storage, QueryInterface $item_query) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, FeedStorageInterface $feed_storage, ItemStorageInterface $item_storage, QueryInterface $item_query, RendererInterface $renderer) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
     $this->feedStorage = $feed_storage;
     $this->itemStorage = $item_storage;
     $this->itemQuery = $item_query;
+    $this->renderer = $renderer;
   }
 
 
@@ -84,7 +95,8 @@ public static function create(ContainerInterface $container, array $configuratio
       $plugin_definition,
       $container->get('entity.manager')->getStorage('aggregator_feed'),
       $container->get('entity.manager')->getStorage('aggregator_item'),
-      $container->get('entity.query')->get('aggregator_item')
+      $container->get('entity.query')->get('aggregator_item'),
+      $container->get('renderer')
     );
   }
 
@@ -161,7 +173,7 @@ public function build() {
         '#url' => $feed->urlInfo(),
         '#attributes' => array('title' => $this->t("View this feed's recent news.")),
       );
-      $read_more = drupal_render($more_link);
+      $read_more = $this->renderer->render($more_link);
       $rendered_items = array();
       foreach ($items as $item) {
         $aggregator_block_item = array(
@@ -169,7 +181,7 @@ public function build() {
           '#url' => $item->urlInfo(),
           '#title' => $item->label(),
         );
-        $rendered_items[] = drupal_render($aggregator_block_item);
+        $rendered_items[] = $this->renderer->render($aggregator_block_item);
       }
       // Only display the block if there are items to show.
       if (count($rendered_items) > 0) {
@@ -178,7 +190,7 @@ public function build() {
           '#items' => $rendered_items,
         );
         return array(
-          '#children' => drupal_render($item_list) . $read_more,
+          '#children' => $this->renderer->render($item_list) . $read_more,
         );
       }
     }
diff --git a/core/modules/aggregator/src/Plugin/views/row/Rss.php b/core/modules/aggregator/src/Plugin/views/row/Rss.php
index 72410e5..d9075fb 100644
--- a/core/modules/aggregator/src/Plugin/views/row/Rss.php
+++ b/core/modules/aggregator/src/Plugin/views/row/Rss.php
@@ -79,7 +79,7 @@ public function render($row) {
       '#options' => $this->options,
       '#row' => $item,
     );
-    return drupal_render_root($build);
+    return $this->renderer->renderRoot($build);
   }
 
 }