* {@inheritdoc}
      */
     public function getConfigTreeBuilder() {
-        $treeBuilder = new TreeBuilder('parameters');
+        $treeBuilder = new TreeBuilder('rapsys_air');
 
         // Here you should define the parameters that are allowed to
         // configure your bundle. See the documentation linked above for
                        ->getRootNode()
                                ->addDefaultsIfNotSet()
                                ->children()
-                                       ->arrayNode('rapsys_air')
-                                               ->addDefaultsIfNotSet()
-                                               ->children()
-                                                       ->scalarNode('logo')->defaultValue($defaults['logo'])->treatNullLike($defaults['logo'])->isRequired()->end()
-                                                       ->scalarNode('title')->defaultValue($defaults['title'])->treatNullLike($defaults['title'])->isRequired()->end()
-                                                       ->scalarNode('contact_name')->defaultValue($defaults['contact_name'])->treatNullLike($defaults['contact_name'])->isRequired()->end()
-                                                       ->scalarNode('contact_mail')->defaultValue($defaults['contact_mail'])->treatNullLike($defaults['contact_mail'])->isRequired()->end()
-                                               ->end()
-                                       ->end()
+                                       ->scalarNode('logo')->defaultValue($defaults['logo'])->treatNullLike($defaults['logo'])->cannotBeEmpty()->end()
+                                       ->scalarNode('title')->defaultValue($defaults['title'])->treatNullLike($defaults['title'])->cannotBeEmpty()->end()
+                                       ->scalarNode('contact_name')->defaultValue($defaults['contact_name'])->treatNullLike($defaults['contact_name'])->cannotBeEmpty()->end()
+                                       ->scalarNode('contact_mail')->defaultValue($defaults['contact_mail'])->treatNullLike($defaults['contact_mail'])->cannotBeEmpty()->end()
                                ->end()
                        ->end();