diff --git a/src/Symfony/Bundle/SwiftmailerBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/SwiftmailerBundle/DependencyInjection/Configuration.php
index d040ac48559ff..c04c1f826cd12 100644
--- a/src/Symfony/Bundle/SwiftmailerBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/SwiftmailerBundle/DependencyInjection/Configuration.php
@@ -61,7 +61,6 @@ public function getConfigTree()
                 ->end()
             ->end()
             ->arrayNode('spool')
-                ->addDefaultsIfNotSet()
                 ->scalarNode('type')->defaultValue('file')->end()
                 ->scalarNode('path')->defaultValue('%kernel.cache_dir%/swiftmailer/spool')->end()
             ->end()