diff --git a/src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php b/src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php
index 2108980131..14ae36f950 100644
--- a/src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php
@@ -107,7 +107,7 @@ abstract class AbstractAuthenticationListener implements ListenerInterface
      *
      * @param Event $event An Event instance
      */
-    public function handle(EventInterface $event)
+    public final function handle(EventInterface $event)
     {
         $request = $event->get('request');
 
diff --git a/src/Symfony/Component/Security/Http/Firewall/AbstractPreAuthenticatedListener.php b/src/Symfony/Component/Security/Http/Firewall/AbstractPreAuthenticatedListener.php
index 72808f5706..bba0466da3 100644
--- a/src/Symfony/Component/Security/Http/Firewall/AbstractPreAuthenticatedListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/AbstractPreAuthenticatedListener.php
@@ -50,7 +50,7 @@ abstract class AbstractPreAuthenticatedListener implements ListenerInterface
      *
      * @param EventInterface $event An EventInterface instance
      */
-    public function handle(EventInterface $event)
+    public final function handle(EventInterface $event)
     {
         $request = $event->get('request');
 
diff --git a/src/Symfony/Component/Security/Http/Firewall/X509AuthenticationListener.php b/src/Symfony/Component/Security/Http/Firewall/X509AuthenticationListener.php
index 22b62dc98d..54e3d3faf3 100644
--- a/src/Symfony/Component/Security/Http/Firewall/X509AuthenticationListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/X509AuthenticationListener.php
@@ -25,8 +25,8 @@ use Symfony\Component\Security\Core\Exception\BadCredentialsException;
  */
 class X509AuthenticationListener extends AbstractPreAuthenticatedListener
 {
-    protected $userKey;
-    protected $credentialKey;
+    private $userKey;
+    private $credentialKey;
 
     public function __construct(SecurityContextInterface $securityContext, AuthenticationManagerInterface $authenticationManager, $providerKey, $userKey = 'SSL_CLIENT_S_DN_Email', $credentialKey = 'SSL_CLIENT_S_DN', LoggerInterface $logger = null, EventDispatcherInterface $eventDispatcher = null)
     {