diff --git a/Twig/Extension.php b/Twig/Extension.php
index 867e6fe..70649b1 100644
--- a/Twig/Extension.php
+++ b/Twig/Extension.php
@@ -10,7 +10,7 @@
 
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
-class Extension extends \Twig_Extension
+class Extension extends \Twig_Extension implements \Twig_Extension_GlobalsInterface
 {
 
     protected $legacyApplication;
diff --git a/composer.json b/composer.json
index d79da87..866eebc 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
         "symfony/http-foundation": "~2.2",
         "doctrine/annotations": "~1.0",
         "webfactory/dom": "~1.0, >= 1.0.15",
-        "twig/twig": "~1.10"
+        "twig/twig": "^1.23"
 
     }