diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index 7b491d7..2baac26 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -27,7 +27,7 @@ class Configuration implements ConfigurationInterface
                     ->prototype('scalar')
                     ->end()
                 ->end()
-                ->booleanNode('default_sections_opened')->defaultValue(true)->end()
+                ->booleanNode('default_sections_opened')->defaultTrue()->end()
                 ->arrayNode('motd')
                     ->addDefaultsIfNotSet()
                     ->children()
@@ -132,7 +132,7 @@ class Configuration implements ConfigurationInterface
                                 })
                             ->end()
                         ->end()
-                        ->booleanNode('entity_to_choice')->defaultValue(true)->end()
+                        ->booleanNode('entity_to_choice')->defaultTrue()->end()
                     ->end()
                 ->end()
                 ->arrayNode('swagger')
@@ -147,10 +147,10 @@ class Configuration implements ConfigurationInterface
                                 ->children()
                                     ->scalarNode('title')->defaultValue('Symfony2')->end()
                                     ->scalarNode('description')->defaultValue('My awesome Symfony2 app!')->end()
-                                    ->scalarNode('TermsOfServiceUrl')->defaultValue(null)->end()
-                                    ->scalarNode('contact')->defaultValue(null)->end()
-                                    ->scalarNode('license')->defaultValue(null)->end()
-                                    ->scalarNode('licenseUrl')->defaultValue(null)->end()
+                                    ->scalarNode('TermsOfServiceUrl')->defaultNull()->end()
+                                    ->scalarNode('contact')->defaultNull()->end()
+                                    ->scalarNode('license')->defaultNull()->end()
+                                    ->scalarNode('licenseUrl')->defaultNull()->end()
                                 ->end()
                         ->end()
                     ->end()
@@ -158,7 +158,7 @@ class Configuration implements ConfigurationInterface
                 ->arrayNode('cache')
                     ->addDefaultsIfNotSet()
                     ->children()
-                        ->booleanNode('enabled')->defaultValue(false)->end()
+                        ->booleanNode('enabled')->defaultFalse()->end()
                         ->scalarNode('file')->defaultValue('%kernel.cache_dir%/api-doc.cache')->end()
                     ->end()
                 ->end()