diff --git a/DependencyInjection/TheodoEvolutionSessionExtension.php b/DependencyInjection/TheodoEvolutionSessionExtension.php
index afc6a48..a2ca5d7 100644
--- a/DependencyInjection/TheodoEvolutionSessionExtension.php
+++ b/DependencyInjection/TheodoEvolutionSessionExtension.php
@@ -36,8 +36,8 @@ public function load(array $configs, ContainerBuilder $container)
      */
     private function addBagManager(ContainerBuilder $container, $config)
     {
+        $managerAlias = 'theodo_evolution.session.bag_manager';
         if (isset($config['bag_manager_service']) && isset($config['bag_configuration_service'])) {
-            $managerAlias = 'theodo_evolution.session.bag_manager';
             $managerId = $config['bag_manager_service'];
             if ($managerAlias !== $managerId) {
                 $container->setAlias($managerAlias, $managerId);
@@ -57,7 +57,7 @@ private function addBagManager(ContainerBuilder $container, $config)
                 'theodo_evolution.session.bag_manager_configuration.class',
                 $config['bag_manager']['configuration_class']
             );
+            $container->setAlias($managerAlias, 'theodo_evolution.session.bag_manager_default');
         }
-
     }
 }