diff --git a/src/Behat/MinkExtension/Extension.php b/src/Behat/MinkExtension/Extension.php
index 608884c..92a5480 100644
--- a/src/Behat/MinkExtension/Extension.php
+++ b/src/Behat/MinkExtension/Extension.php
@@ -166,240 +166,240 @@ class Extension implements BaseExtension
 
         $builder->
             children()->
-            scalarNode('mink_loader')->
-            defaultValue(isset($config['mink_loader']) ? $config['mink_loader'] : null)->
-            end()->
-            scalarNode('base_url')->
-            defaultValue(isset($config['base_url']) ? $config['base_url'] : null)->
-            end()->
-            scalarNode('files_path')->
-            defaultValue(isset($config['files_path']) ? $config['files_path'] : null)->
-            end()->
-            booleanNode('show_auto')->
-            defaultValue(isset($config['show_auto']) ? 'true' === $config['show_auto'] : false)->
-            end()->
-            scalarNode('show_cmd')->
-            defaultValue(isset($config['show_cmd']) ? $config['show_cmd'] : null)->
-            end()->
-            scalarNode('show_tmp_dir')->
-            defaultValue(isset($config['show_tmp_dir']) ? $config['show_tmp_dir'] : sys_get_temp_dir())->
-            end()->
-            scalarNode('default_session')->
-            defaultValue(isset($config['default_session']) ? $config['default_session'] : 'goutte')->
-            end()->
-            scalarNode('javascript_session')->
-            defaultValue(isset($config['javascript_session']) ? $config['javascript_session'] : 'selenium2')->
-            end()->
-            scalarNode('browser_name')->
-            defaultValue(isset($config['browser_name']) ? $config['browser_name'] : 'firefox')->
-            end()->
-            arrayNode('goutte')->
-            children()->
-            arrayNode('server_parameters')->
-            useAttributeAsKey('key')->
-            prototype('variable')->end()->
-            end()->
-            arrayNode('guzzle_parameters')->
-            useAttributeAsKey('key')->
-            prototype('variable')->end()->
-            end()->
-            end()->
-            end()->
-            arrayNode('sahi')->
-            children()->
-            scalarNode('sid')->
-            defaultValue(isset($config['sahi']['sid']) ? $config['sahi']['sid'] : null)->
-            end()->
-            scalarNode('host')->
-            defaultValue('localhost')->
-            end()->
-            scalarNode('port')->
-            defaultValue(isset($config['sahi']['port']) ? $config['sahi']['port'] : 9999)->
-            end()->
-            scalarNode('browser')->
-            defaultValue(isset($config['sahi']['browser']) ? $config['sahi']['browser'] : null)->
-            end()->
-            scalarNode('limit')->
-            defaultValue(isset($config['sahi']['limit']) ? $config['sahi']['limit'] : 600)->
-            end()->
-            end()->
-            end()->
-            arrayNode('zombie')->
-            children()->
-            scalarNode('host')->
-            defaultValue(isset($config['zombie']['host']) ? $config['zombie']['host'] : '127.0.0.1')->
-            end()->
-            scalarNode('port')->
-            defaultValue(isset($config['zombie']['port']) ? $config['zombie']['port'] : 8124)->
-            end()->
-            scalarNode('auto_server')->
-            defaultValue(isset($config['zombie']['auto_server']) ? $config['zombie']['auto_server'] : true)->
-            end()->
-            scalarNode('node_bin')->
-            defaultValue(isset($config['zombie']['node_bin']) ? $config['zombie']['node_bin'] : 'node')->
-            end()->
-            scalarNode('server_path')->
-            defaultValue(isset($config['zombie']['server_path']) ? $config['zombie']['server_path'] : null)->
-            end()->
-            scalarNode('threshold')->
-            defaultValue(isset($config['zombie']['threshold']) ? $config['zombie']['threshold'] : 2000000)->
-            end()->
-            scalarNode('node_modules_path')->
-            defaultValue(isset($config['zombie']['node_modules_path']) ? $config['zombie']['node_modules_path'] : '')->
-            end()->
-            end()->
-            end()->
-            arrayNode('selenium')->
-            children()->
-            scalarNode('host')->
-            defaultValue(isset($config['selenium']['host']) ? $config['selenium']['host'] : '127.0.0.1')->
-            end()->
-            scalarNode('port')->
-            defaultValue(isset($config['selenium']['port']) ? $config['selenium']['port'] : 4444)->
-            end()->
-            scalarNode('browser')->
-            defaultValue(isset($config['selenium']['browser']) ? $config['selenium']['browser'] : '*%behat.mink.browser_name%')->
-            end()->
-            end()->
-            end()->
-            arrayNode('selenium2')->
-            children()->
-            scalarNode('browser')->
-            defaultValue(isset($config['selenium2']['browser']) ? $config['selenium2']['browser'] : '%behat.mink.browser_name%')->
-            end()->
-            arrayNode('capabilities')->
-            normalizeKeys(false)->
-            children()->
-            scalarNode('browserName')->
-            defaultValue(isset($config['selenium2']['capabilities']['browserName']) ? $config['selenium2']['capabilities']['browserName'] : 'firefox')->
-            end()->
-            scalarNode('version')->
-            defaultValue(isset($config['selenium2']['capabilities']['version']) ? $config['selenium2']['capabilities']['version'] : "9")->
-            end()->
-            scalarNode('platform')->
-            defaultValue(isset($config['selenium2']['capabilities']['platform']) ? $config['selenium2']['capabilities']['platform'] : 'ANY')->
-            end()->
-            scalarNode('browserVersion')->
-            defaultValue(isset($config['selenium2']['capabilities']['browserVersion']) ? $config['selenium2']['capabilities']['browserVersion'] : "9")->
-            end()->
-            scalarNode('browser')->
-            defaultValue(isset($config['selenium2']['capabilities']['browser']) ? $config['selenium2']['capabilities']['browser'] : 'firefox')->
-            end()->
-            scalarNode('ignoreZoomSetting')->
-            defaultValue(isset($config['selenium2']['capabilities']['ignoreZoomSetting']) ? $config['selenium2']['capabilities']['ignoreZoomSetting'] : 'false')->
-            end()->
-            scalarNode('name')->
-            defaultValue(isset($config['selenium2']['capabilities']['name']) ? $config['selenium2']['capabilities']['name'] : 'Behat Test')->
-            end()->
-            scalarNode('deviceOrientation')->
-            defaultValue(isset($config['selenium2']['capabilities']['deviceOrientation']) ? $config['selenium2']['capabilities']['deviceOrientation'] : 'portrait')->
-            end()->
-            scalarNode('deviceType')->
-            defaultValue(isset($config['selenium2']['capabilities']['deviceType']) ? $config['selenium2']['capabilities']['deviceType'] : 'tablet')->
-            end()->
-            scalarNode('selenium-version')->
-            defaultValue(isset($config['selenium2']['capabilities']['selenium-version']) ? $config['selenium2']['capabilities']['selenium-version'] : '2.31.0')->
-            end()->
-            scalarNode('max-duration')->
-            defaultValue(isset($config['selenium2']['capabilities']['max-duration']) ? $config['selenium2']['capabilities']['max-duration'] : '300')->
-            end()->
-            booleanNode('javascriptEnabled')->end()->
-            booleanNode('databaseEnabled')->end()->
-            booleanNode('locationContextEnabled')->end()->
-            booleanNode('applicationCacheEnabled')->end()->
-            booleanNode('browserConnectionEnabled')->end()->
-            booleanNode('webStorageEnabled')->end()->
-            booleanNode('rotatable')->end()->
-            booleanNode('acceptSslCerts')->end()->
-            booleanNode('nativeEvents')->end()->
-            booleanNode('passed')->end()->
-            booleanNode('record-video')->end()->
-            booleanNode('record-screenshots')->end()->
-            booleanNode('capture-html')->end()->
-            booleanNode('disable-popup-handler')->end()->
-            arrayNode('proxy')->
-            children()->
-            scalarNode('proxyType')->end()->
-            scalarNode('proxyAuthconfigUrl')->end()->
-            scalarNode('ftpProxy')->end()->
-            scalarNode('httpProxy')->end()->
-            scalarNode('sslProxy')->end()->
-            end()->
-            validate()->
-            ifTrue(function ($v) {
-                return empty($v);
-            })->
-            thenUnset()->
-            end()->
-            end()->
-            arrayNode('firefox')->
-            children()->
-            scalarNode('profile')->
-            validate()->
-            ifTrue(function ($v) {
-                return !file_exists($v);
-            })->
-            thenInvalid('Cannot find profile zip file %s')->
-            end()->
-            end()->
-            scalarNode('binary')->end()->
-            end()->
-            end()->
-            arrayNode('chrome')->
-            children()->
-            arrayNode('switches')->
-            prototype('scalar')->end()->
-            end()->
-            scalarNode('binary')->end()->
-            arrayNode('extensions')->
-            prototype('scalar')->end()->
-            end()->
-            end()->
-            end()->
-            end()->
-            end()->
-            scalarNode('wd_host')->
-            defaultValue(isset($config['selenium2']['wd_host']) ? $config['selenium2']['wd_host'] : 'http://localhost:4444/wd/hub')->
-            end()->
-            end()->
-            end()->
-            arrayNode('saucelabs')->
-            children()->
-            scalarNode('username')->
-            defaultValue(getenv('SAUCE_USERNAME'))->
-            end()->
-            scalarNode('access_key')->
-            defaultValue(getenv('SAUCE_ACCESS_KEY'))->
-            end()->
-            booleanNode('connect')->
-            defaultValue(isset($config['saucelabs']['connect']) ? 'true' === $config['saucelabs']['connect'] : false)->
-            end()->
-            scalarNode('browser')->
-            defaultValue(isset($config['saucelabs']['browser']) ? $config['saucelabs']['browser'] : 'firefox')->
-            end()->
-            arrayNode('capabilities')->
-            children()->
-            scalarNode('name')->
-            defaultValue(isset($config['saucelabs']['name']) ? $config['saucelabs']['name'] : 'Behat feature suite')->
-            end()->
-            scalarNode('platform')->
-            defaultValue(isset($config['saucelabs']['platform']) ? $config['saucelabs']['platform'] : 'Linux')->
-            end()->
-            scalarNode('version')->
-            defaultValue(isset($config['saucelabs']['version']) ? $config['saucelabs']['version'] : '21')->
-            end()->
-            scalarNode('deviceType')->
-            defaultValue(isset($config['saucelabs']['deviceType']) ? $config['saucelabs']['deviceType'] : null)->
-            end()->
-            scalarNode('deviceOrientation')->
-            defaultValue(isset($config['saucelabs']['deviceOrientation']) ? $config['saucelabs']['deviceOrientation'] : null)->
-            end()->
-            end()->
-            end()->
-            end()->
-            end()->
-            end()->
-            end();
+                scalarNode('mink_loader')->
+                    defaultValue(isset($config['mink_loader']) ? $config['mink_loader'] : null)->
+                end()->
+                scalarNode('base_url')->
+                    defaultValue(isset($config['base_url']) ? $config['base_url'] : null)->
+                end()->
+                scalarNode('files_path')->
+                    defaultValue(isset($config['files_path']) ? $config['files_path'] : null)->
+                end()->
+                booleanNode('show_auto')->
+                    defaultValue(isset($config['show_auto']) ? 'true' === $config['show_auto'] : false)->
+                end()->
+                scalarNode('show_cmd')->
+                    defaultValue(isset($config['show_cmd']) ? $config['show_cmd'] : null)->
+                end()->
+                scalarNode('show_tmp_dir')->
+                    defaultValue(isset($config['show_tmp_dir']) ? $config['show_tmp_dir'] : sys_get_temp_dir())->
+                end()->
+                scalarNode('default_session')->
+                    defaultValue(isset($config['default_session']) ? $config['default_session'] : 'goutte')->
+                end()->
+                scalarNode('javascript_session')->
+                    defaultValue(isset($config['javascript_session']) ? $config['javascript_session'] : 'selenium2')->
+                end()->
+                scalarNode('browser_name')->
+                    defaultValue(isset($config['browser_name']) ? $config['browser_name'] : 'firefox')->
+                end()->
+                arrayNode('goutte')->
+                    children()->
+                        arrayNode('server_parameters')->
+                            useAttributeAsKey('key')->
+                            prototype('variable')->end()->
+                        end()->
+                        arrayNode('guzzle_parameters')->
+                            useAttributeAsKey('key')->
+                            prototype('variable')->end()->
+                        end()->
+                    end()->
+                end()->
+                arrayNode('sahi')->
+                    children()->
+                        scalarNode('sid')->
+                            defaultValue(isset($config['sahi']['sid']) ? $config['sahi']['sid'] : null)->
+                        end()->
+                        scalarNode('host')->
+                            defaultValue('localhost')->
+                        end()->
+                        scalarNode('port')->
+                            defaultValue(isset($config['sahi']['port']) ? $config['sahi']['port'] : 9999)->
+                        end()->
+                        scalarNode('browser')->
+                            defaultValue(isset($config['sahi']['browser']) ? $config['sahi']['browser'] : null)->
+                        end()->
+                        scalarNode('limit')->
+                            defaultValue(isset($config['sahi']['limit']) ? $config['sahi']['limit'] : 600)->
+                        end()->
+                    end()->
+                end()->
+                arrayNode('zombie')->
+                    children()->
+                        scalarNode('host')->
+                            defaultValue(isset($config['zombie']['host']) ? $config['zombie']['host'] : '127.0.0.1')->
+                        end()->
+                        scalarNode('port')->
+                            defaultValue(isset($config['zombie']['port']) ? $config['zombie']['port'] : 8124)->
+                        end()->
+                        scalarNode('auto_server')->
+                            defaultValue(isset($config['zombie']['auto_server']) ? $config['zombie']['auto_server'] : true)->
+                        end()->
+                        scalarNode('node_bin')->
+                            defaultValue(isset($config['zombie']['node_bin']) ? $config['zombie']['node_bin'] : 'node')->
+                        end()->
+                        scalarNode('server_path')->
+                            defaultValue(isset($config['zombie']['server_path']) ? $config['zombie']['server_path'] : null)->
+                        end()->
+                        scalarNode('threshold')->
+                            defaultValue(isset($config['zombie']['threshold']) ? $config['zombie']['threshold'] : 2000000)->
+                        end()->
+                        scalarNode('node_modules_path')->
+                            defaultValue(isset($config['zombie']['node_modules_path']) ? $config['zombie']['node_modules_path'] : '')->
+                        end()->
+                    end()->
+                end()->
+                arrayNode('selenium')->
+                    children()->
+                        scalarNode('host')->
+                            defaultValue(isset($config['selenium']['host']) ? $config['selenium']['host'] : '127.0.0.1')->
+                        end()->
+                        scalarNode('port')->
+                            defaultValue(isset($config['selenium']['port']) ? $config['selenium']['port'] : 4444)->
+                        end()->
+                        scalarNode('browser')->
+                            defaultValue(isset($config['selenium']['browser']) ? $config['selenium']['browser'] : '*%behat.mink.browser_name%')->
+                        end()->
+                    end()->
+                end()->
+                arrayNode('selenium2')->
+                    children()->
+                        scalarNode('browser')->
+                            defaultValue(isset($config['selenium2']['browser']) ? $config['selenium2']['browser'] : '%behat.mink.browser_name%')->
+                        end()->
+                        arrayNode('capabilities')->
+                            normalizeKeys(false)->
+                            children()->
+                                scalarNode('browserName')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['browserName']) ? $config['selenium2']['capabilities']['browserName'] : 'firefox')->
+                                end()->
+                                scalarNode('version')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['version']) ? $config['selenium2']['capabilities']['version'] : "9")->
+                                end()->
+                                scalarNode('platform')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['platform']) ? $config['selenium2']['capabilities']['platform'] : 'ANY')->
+                                end()->
+                                scalarNode('browserVersion')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['browserVersion']) ? $config['selenium2']['capabilities']['browserVersion'] : "9")->
+                                end()->
+                                scalarNode('browser')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['browser']) ? $config['selenium2']['capabilities']['browser'] : 'firefox')->
+                                end()->
+                                scalarNode('ignoreZoomSetting')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['ignoreZoomSetting']) ? $config['selenium2']['capabilities']['ignoreZoomSetting'] : 'false')->
+                                end()->
+                                scalarNode('name')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['name']) ? $config['selenium2']['capabilities']['name'] : 'Behat Test')->
+                                end()->
+                                scalarNode('deviceOrientation')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['deviceOrientation']) ? $config['selenium2']['capabilities']['deviceOrientation'] : 'portrait')->
+                                end()->
+                                scalarNode('deviceType')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['deviceType']) ? $config['selenium2']['capabilities']['deviceType'] : 'tablet')->
+                                end()->
+                                scalarNode('selenium-version')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['selenium-version']) ? $config['selenium2']['capabilities']['selenium-version'] : '2.31.0')->
+                                end()->
+                                scalarNode('max-duration')->
+                                    defaultValue(isset($config['selenium2']['capabilities']['max-duration']) ? $config['selenium2']['capabilities']['max-duration'] : '300')->
+                                end()->
+                                booleanNode('javascriptEnabled')->end()->
+                                booleanNode('databaseEnabled')->end()->
+                                booleanNode('locationContextEnabled')->end()->
+                                booleanNode('applicationCacheEnabled')->end()->
+                                booleanNode('browserConnectionEnabled')->end()->
+                                booleanNode('webStorageEnabled')->end()->
+                                booleanNode('rotatable')->end()->
+                                booleanNode('acceptSslCerts')->end()->
+                                booleanNode('nativeEvents')->end()->
+                                booleanNode('passed')->end()->
+                                booleanNode('record-video')->end()->
+                                booleanNode('record-screenshots')->end()->
+                                booleanNode('capture-html')->end()->
+                                booleanNode('disable-popup-handler')->end()->
+                                arrayNode('proxy')->
+                                    children()->
+                                        scalarNode('proxyType')->end()->
+                                        scalarNode('proxyAuthconfigUrl')->end()->
+                                        scalarNode('ftpProxy')->end()->
+                                        scalarNode('httpProxy')->end()->
+                                        scalarNode('sslProxy')->end()->
+                                    end()->
+                                    validate()->
+                                        ifTrue(function ($v) {
+                                            return empty($v);
+                                        })->
+                                        thenUnset()->
+                                    end()->
+                                end()->
+                                arrayNode('firefox')->
+                                    children()->
+                                        scalarNode('profile')->
+                                            validate()->
+                                            ifTrue(function ($v) {
+                                                return !file_exists($v);
+                                            })->
+                                                thenInvalid('Cannot find profile zip file %s')->
+                                            end()->
+                                        end()->
+                                        scalarNode('binary')->end()->
+                                    end()->
+                                end()->
+                                arrayNode('chrome')->
+                                    children()->
+                                        arrayNode('switches')->
+                                            prototype('scalar')->end()->
+                                        end()->
+                                        scalarNode('binary')->end()->
+                                        arrayNode('extensions')->
+                                            prototype('scalar')->end()->
+                                        end()->
+                                    end()->
+                                end()->
+                            end()->
+                        end()->
+                        scalarNode('wd_host')->
+                            defaultValue(isset($config['selenium2']['wd_host']) ? $config['selenium2']['wd_host'] : 'http://localhost:4444/wd/hub')->
+                        end()->
+                    end()->
+                end()->
+                arrayNode('saucelabs')->
+                    children()->
+                        scalarNode('username')->
+                            defaultValue(getenv('SAUCE_USERNAME'))->
+                        end()->
+                        scalarNode('access_key')->
+                            defaultValue(getenv('SAUCE_ACCESS_KEY'))->
+                        end()->
+                        booleanNode('connect')->
+                            defaultValue(isset($config['saucelabs']['connect']) ? 'true' === $config['saucelabs']['connect'] : false)->
+                        end()->
+                        scalarNode('browser')->
+                            defaultValue(isset($config['saucelabs']['browser']) ? $config['saucelabs']['browser'] : 'firefox')->
+                        end()->
+                        arrayNode('capabilities')->
+                            children()->
+                                scalarNode('name')->
+                                    defaultValue(isset($config['saucelabs']['name']) ? $config['saucelabs']['name'] : 'Behat feature suite')->
+                                end()->
+                                scalarNode('platform')->
+                                    defaultValue(isset($config['saucelabs']['platform']) ? $config['saucelabs']['platform'] : 'Linux')->
+                                end()->
+                                scalarNode('version')->
+                                    defaultValue(isset($config['saucelabs']['version']) ? $config['saucelabs']['version'] : '21')->
+                                end()->
+                                scalarNode('deviceType')->
+                                    defaultValue(isset($config['saucelabs']['deviceType']) ? $config['saucelabs']['deviceType'] : null)->
+                                end()->
+                                scalarNode('deviceOrientation')->
+                                    defaultValue(isset($config['saucelabs']['deviceOrientation']) ? $config['saucelabs']['deviceOrientation'] : null)->
+                                end()->
+                            end()->
+                        end()->
+                    end()->
+                end()->
+            end()->
+        end();
     }
 
     /**