diff --git a/openedx/core/djangoapps/notifications/tests/test_views.py b/openedx/core/djangoapps/notifications/tests/test_views.py
index 745b690b5c..de02141745 100644
--- a/openedx/core/djangoapps/notifications/tests/test_views.py
+++ b/openedx/core/djangoapps/notifications/tests/test_views.py
@@ -443,7 +443,7 @@ class NotificationReadAPIViewTestCase(APITestCase):
         response = self.client.patch(self.url, data)
 
         self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
-        self.assertEqual(response.data["detail"], 'Not found.')
+        self.assertEqual(response.data["detail"].code, 'not_found')
 
     def test_mark_notification_read_with_app_name_and_notification_id(self):
         # Create a PATCH request to mark notification as read for existing app e.g 'discussion' and notification_id: 2