diff --git a/cookbook/security/api_key_authentication.rst b/cookbook/security/api_key_authentication.rst
index 0feefca9a4b..8fb6dfbdb38 100644
--- a/cookbook/security/api_key_authentication.rst
+++ b/cookbook/security/api_key_authentication.rst
@@ -31,7 +31,6 @@ value and then a User object is created::
     use Symfony\Component\Security\Core\Authentication\Token\PreAuthenticatedToken;
     use Symfony\Component\HttpFoundation\Request;
     use Symfony\Component\Security\Core\User\UserProviderInterface;
-    use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
     use Symfony\Component\Security\Core\Exception\BadCredentialsException;
 
     class ApiKeyAuthenticator implements SimplePreAuthenticatorInterface