diff --git a/src/Symfony/Component/Security/Core/Exception/UsernameNotFoundException.php b/src/Symfony/Component/Security/Core/Exception/UsernameNotFoundException.php
index 11607d336d..8b72dc2ae0 100644
--- a/src/Symfony/Component/Security/Core/Exception/UsernameNotFoundException.php
+++ b/src/Symfony/Component/Security/Core/Exception/UsernameNotFoundException.php
@@ -69,4 +69,12 @@ class UsernameNotFoundException extends AuthenticationException
 
         parent::unserialize($parentData);
     }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getMessageData()
+    {
+        return array('{{ username }}' => $this->username);
+    }
 }
diff --git a/src/Symfony/Component/Security/Core/Tests/Exception/UsernameNotFoundExceptionTest.php b/src/Symfony/Component/Security/Core/Tests/Exception/UsernameNotFoundExceptionTest.php
new file mode 100644
index 0000000000..b460229ac6
--- /dev/null
+++ b/src/Symfony/Component/Security/Core/Tests/Exception/UsernameNotFoundExceptionTest.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Tests\Core\Exception;
+
+use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
+
+class UsernameNotFoundExceptionTest extends \PHPUnit_Framework_TestCase
+{
+    public function testGetMessageData()
+    {
+        $exception = new UsernameNotFoundException('Username could not be found.');
+        $this->assertEquals(array('{{ username }}' => null), $exception->getMessageData());
+        $exception->setUsername('username');
+        $this->assertEquals(array('{{ username }}' => 'username'), $exception->getMessageData());
+    }
+}