diff --git a/security/access_denied_handler.rst b/security/access_denied_handler.rst
index 5671b0538a1..404c222e4c9 100644
--- a/security/access_denied_handler.rst
+++ b/security/access_denied_handler.rst
@@ -27,6 +27,7 @@ unauthenticated user tries to access a protected resource::
 
     use Symfony\Component\HttpFoundation\RedirectResponse;
     use Symfony\Component\HttpFoundation\Request;
+    use Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface;
     use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
     use Symfony\Component\Security\Core\Exception\AuthenticationException;
     use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
@@ -41,7 +42,9 @@ unauthenticated user tries to access a protected resource::
         public function start(Request $request, AuthenticationException $authException = null): RedirectResponse
         {
             // add a custom flash message and redirect to the login page
-            $request->getSession()->getFlashBag()->add('note', 'You have to login in order to access this page.');
+            /** @var FlashBagInterface */
+            $flashBag = $request->getSession()->getBag('flashes');
+            $flashBag->add('note', 'You have to login in order to access this page.');
 
             return new RedirectResponse($this->urlGenerator->generate('security_login'));
         }