diff --git a/src/Symfony/Component/Security/Guard/Firewall/GuardAuthenticationListener.php b/src/Symfony/Component/Security/Guard/Firewall/GuardAuthenticationListener.php
index 9e2a8868f2..d3be9abbe9 100644
--- a/src/Symfony/Component/Security/Guard/Firewall/GuardAuthenticationListener.php
+++ b/src/Symfony/Component/Security/Guard/Firewall/GuardAuthenticationListener.php
@@ -162,7 +162,7 @@ class GuardAuthenticationListener implements ListenerInterface
 
         if (null === $this->rememberMeServices) {
             if (null !== $this->logger) {
-                $this->logger->info('Remember me skipped: it is not configured for the firewall', array('authenticator' => get_class($guardAuthenticator)));
+                $this->logger->info('Remember me skipped: it is not configured for the firewall.', array('authenticator' => get_class($guardAuthenticator)));
             }
 
             return;
diff --git a/src/Symfony/Component/Security/Guard/GuardAuthenticatorHandler.php b/src/Symfony/Component/Security/Guard/GuardAuthenticatorHandler.php
index 5be7eb5564..465b45a957 100644
--- a/src/Symfony/Component/Security/Guard/GuardAuthenticatorHandler.php
+++ b/src/Symfony/Component/Security/Guard/GuardAuthenticatorHandler.php
@@ -68,7 +68,7 @@ class GuardAuthenticatorHandler
         }
 
         throw new \UnexpectedValueException(sprintf(
-            'The %s::onAuthenticationSuccess method must return null or a Response object. You returned %s',
+            'The %s::onAuthenticationSuccess method must return null or a Response object. You returned %s.',
             get_class($guardAuthenticator),
             is_object($response) ? get_class($response) : gettype($response)
         ));
@@ -117,7 +117,7 @@ class GuardAuthenticatorHandler
         }
 
         throw new \UnexpectedValueException(sprintf(
-            'The %s::onAuthenticationFailure method must return null or a Response object. You returned %s',
+            'The %s::onAuthenticationFailure method must return null or a Response object. You returned %s.',
             get_class($guardAuthenticator),
             is_object($response) ? get_class($response) : gettype($response)
         ));
diff --git a/src/Symfony/Component/Security/Guard/Provider/GuardAuthenticationProvider.php b/src/Symfony/Component/Security/Guard/Provider/GuardAuthenticationProvider.php
index c21af4c49c..4fefee3b89 100644
--- a/src/Symfony/Component/Security/Guard/Provider/GuardAuthenticationProvider.php
+++ b/src/Symfony/Component/Security/Guard/Provider/GuardAuthenticationProvider.php
@@ -52,7 +52,7 @@ class GuardAuthenticationProvider implements AuthenticationProviderInterface
     public function authenticate(TokenInterface $token)
     {
         if (!$this->supports($token)) {
-            throw new \InvalidArgumentException('GuardAuthenticationProvider only supports NonAuthenticatedGuardToken');
+            throw new \InvalidArgumentException('GuardAuthenticationProvider only supports GuardTokenInterface.');
         }
 
         if (!$token instanceof PreAuthenticationGuardToken) {
@@ -87,7 +87,7 @@ class GuardAuthenticationProvider implements AuthenticationProviderInterface
         }
 
         throw new \LogicException(sprintf(
-            'The correct GuardAuthenticator could not be found for unique key "%s". The listener and provider should be passed the same list of authenticators!?',
+            'The correct GuardAuthenticator could not be found for unique key "%s". The listener and provider should be passed the same list of authenticators.',
             $token->getGuardProviderKey()
         ));
     }
@@ -99,7 +99,7 @@ class GuardAuthenticationProvider implements AuthenticationProviderInterface
 
         if (!$user instanceof UserInterface) {
             throw new \UnexpectedValueException(sprintf(
-                'The %s::authenticate method must return a UserInterface. You returned %s',
+                'The %s::authenticate method must return a UserInterface. You returned %s.',
                 get_class($guardAuthenticator),
                 is_object($user) ? get_class($user) : gettype($user)
             ));
@@ -113,7 +113,7 @@ class GuardAuthenticationProvider implements AuthenticationProviderInterface
         $authenticatedToken = $guardAuthenticator->createAuthenticatedToken($user, $this->providerKey);
         if (!$authenticatedToken instanceof TokenInterface) {
             throw new \UnexpectedValueException(sprintf(
-                'The %s::createAuthenticatedToken method must return a TokenInterface. You returned %s',
+                'The %s::createAuthenticatedToken method must return a TokenInterface. You returned %s.',
                 get_class($guardAuthenticator),
                 is_object($authenticatedToken) ? get_class($authenticatedToken) : gettype($authenticatedToken)
             ));
diff --git a/src/Symfony/Component/Security/Guard/Token/PreAuthenticationGuardToken.php b/src/Symfony/Component/Security/Guard/Token/PreAuthenticationGuardToken.php
index 8950f93533..cc52ec2b8a 100644
--- a/src/Symfony/Component/Security/Guard/Token/PreAuthenticationGuardToken.php
+++ b/src/Symfony/Component/Security/Guard/Token/PreAuthenticationGuardToken.php
@@ -51,6 +51,6 @@ class PreAuthenticationGuardToken extends AbstractToken implements GuardTokenInt
 
     public function setAuthenticated($authenticated)
     {
-        throw new \Exception('The PreAuthenticationGuardToken is *always* not authenticated');
+        throw new \LogicException('The PreAuthenticationGuardToken is *always* not authenticated.');
     }
 }