diff --git a/security/user_provider.rst b/security/user_provider.rst
index f064507045d..7c23617b4a9 100644
--- a/security/user_provider.rst
+++ b/security/user_provider.rst
@@ -534,4 +534,5 @@ user provider:
         # ...
 
         App\Security\LoginFormAuthenticator:
-            $userProvider: '@security.user.provider.concrete.backend_users'
+            arguments:
+                $userProvider: '@security.user.provider.concrete.backend_users'