diff --git a/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php b/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
index 9a1658ad84..1f73a670f1 100644
--- a/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
+++ b/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
@@ -19,6 +19,27 @@ class WhosOnlineBlockTest extends KernelTestBase {
   public static $modules = ['system', 'user', 'block', 'views'];
 
   /**
+   * The block being tested.
+   *
+   * @var \Drupal\block\Entity\BlockInterface
+   */
+  protected $block;
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Config\Entity\ConfigEntityStorageInterface
+   */
+  protected $controller;
+
+  /**
+   * The renderer.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+    /**
    * {@inheritdoc}
    */
   protected function setUp() {
@@ -27,6 +48,24 @@ protected function setUp() {
     $this->installSchema('system', ['sequences']);
     $this->installEntitySchema('user');
 
+    $this->controller = $this->container
+        ->get('entity_type.manager')
+        ->getStorage('block');
+
+    // Create a block with only required values.
+    $this->block = $this->controller->create([
+      'plugin' => 'views_block:who_s_online-who_s_online_block',
+      'region' => 'sidebar_first',
+      'id' => 'views_block__who_s_online_who_s_online_block',
+      'theme' => \Drupal::configFactory()->get('system.theme')->get('default'),
+      'label' => "Who's online",
+      'visibility' => [],
+      'weight' => 0,
+    ]);
+    $this->block->save();
+
+    $this->container->get('cache.render')->deleteAll();
+    $this->renderer = $this->container->get('renderer');
   }
 
   /**
@@ -63,21 +102,11 @@ public function testWhosOnlineBlock() {
 
     // Test block output.
     \Drupal::currentUser()->setAccount($user1);
-    // Create a block with only required values.
-    $block = Block::create([
-      'plugin' => 'views_block:who_s_online-who_s_online_block',
-      'region' => 'sidebar_first',
-      'id' => 'views_block__who_s_online_who_s_online_block',
-      'theme' => \Drupal::configFactory()->get('system.theme')->get('default'),
-      'label' => "Who's online",
-      'visibility' => [],
-      'weight' => 0,
-    ]);
-    $block->save();
-    $this->container->get('cache.render')->deleteAll();
-    $render_controller = \Drupal::entityTypeManager()->getViewBuilder($block->getEntityTypeId());
-    $content = $render_controller->view($block, 'block');
-    $this->setRawContent($this->render($content));
+
+    // Test the rendering of a block.
+    $entity = Block::load('views_block__who_s_online_who_s_online_block');
+    $output = entity_view($entity, 'block');
+    $this->setRawContent($this->renderer->renderRoot($output));
     $this->assertRaw('2 users', 'Correct number of online users (2 users).');
     $this->assertText($user1->getUsername(), 'Active user 1 found in online list.');
     $this->assertText($user2->getUsername(), 'Active user 2 found in online list.');