diff --git a/app/code/Magento/AdminNotification/Controller/Adminhtml/Notification/AjaxMarkAsRead.php b/app/code/Magento/AdminNotification/Controller/Adminhtml/Notification/AjaxMarkAsRead.php
index 31a129d57ab90..da797fe12e75a 100644
--- a/app/code/Magento/AdminNotification/Controller/Adminhtml/Notification/AjaxMarkAsRead.php
+++ b/app/code/Magento/AdminNotification/Controller/Adminhtml/Notification/AjaxMarkAsRead.php
@@ -6,12 +6,35 @@
  */
 namespace Magento\AdminNotification\Controller\Adminhtml\Notification;
 
+use Magento\Backend\App\Action;
+use Magento\Framework\Controller\ResultFactory;
+
 class AjaxMarkAsRead extends \Magento\AdminNotification\Controller\Adminhtml\Notification
 {
+    /**
+     * @var \Magento\AdminNotification\Model\NotificationService
+     */
+    private $notificationService;
+
+    /**
+     * @param Action\Context $context
+     * @param \Magento\AdminNotification\Model\NotificationService|null $notificationService
+     * @throws \RuntimeException
+     */
+    public function __construct(
+        Action\Context $context,
+        \Magento\AdminNotification\Model\NotificationService $notificationService = null
+    ) {
+        parent::__construct($context);
+        $this->notificationService = $notificationService?: \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(\Magento\AdminNotification\Model\NotificationService::class);
+    }
+
     /**
      * Mark notification as read (AJAX action)
      *
-     * @return void
+     * @return \Magento\Framework\Controller\Result\Json|void
+     * @throws \InvalidArgumentException
      */
     public function execute()
     {
@@ -21,17 +44,15 @@ public function execute()
         $notificationId = (int)$this->getRequest()->getPost('id');
         $responseData = [];
         try {
-            $this->_objectManager->create(
-                \Magento\AdminNotification\Model\NotificationService::class
-            )->markAsRead(
-                $notificationId
-            );
+            $this->notificationService->markAsRead($notificationId);
             $responseData['success'] = true;
         } catch (\Exception $e) {
             $responseData['success'] = false;
         }
-        $this->getResponse()->representJson(
-            $this->_objectManager->create(\Magento\Framework\Json\Helper\Data::class)->jsonEncode($responseData)
-        );
+
+        /** @var \Magento\Framework\Controller\Result\Json $resultJson */
+        $resultJson = $this->resultFactory->create(ResultFactory::TYPE_JSON);
+        $resultJson->setData($responseData);
+        return $resultJson;
     }
 }