diff --git a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php
index 453ff1092febb..372f80ea0b782 100644
--- a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php
+++ b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php
@@ -459,7 +459,7 @@ protected function createUserDaoProvider($name, $provider, ContainerBuilder $con
 
             $container
                 ->setDefinition($userId, new DefinitionDecorator('security.user.provider.in_memory.user'))
-                ->setArguments(array($username, $user['password'], $user['roles']))
+                ->setArguments(array($username, (string)$user['password'], $user['roles']))
             ;
 
             $definition->addMethodCall('createUser', array(new Reference($userId)));