diff --git a/Resources/config/services.yml b/Resources/config/services.yml
index 282dc68..7cbbcfd 100644
--- a/Resources/config/services.yml
+++ b/Resources/config/services.yml
@@ -11,10 +11,10 @@ services:
     vcr.config:
         class: VCR\Configuration
         calls:
-            - [ enableLibraryHooks, [ %vcr.library_hooks% ]]
-            - [ enableRequestMatchers, [ %vcr.request_matchers% ] ]
-            - [ setCassettePath, [ %vcr.cassette.path% ] ]
-            - [ setStorage, [ %vcr.cassette.type% ] ]
+            - [ enableLibraryHooks, [ "%vcr.library_hooks%" ]]
+            - [ enableRequestMatchers, [ "%vcr.request_matchers%" ] ]
+            - [ setCassettePath, [ "%vcr.cassette.path%" ] ]
+            - [ setStorage, [ "%vcr.cassette.type%" ] ]
 
     vcr.http_client:
         class: VCR\Util\HttpClient
@@ -29,3 +29,4 @@ services:
         arguments:  [ '@vcr.config', '@vcr.http_client', '@vcr.factory' ]
         calls:
             - [ setEventDispatcher, [ '@event_dispatcher' ] ]
+        public: true
diff --git a/composer.json b/composer.json
index 69e8e29..0c98cf8 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "symfony/framework-bundle": "~2.6||~3.0",
+        "symfony/framework-bundle": "~2.6||~3.0||~4.0",
         "php-vcr/php-vcr": "~1.2"
     },
     "autoload": {