diff --git a/src/Oauth2/Server.php b/src/Oauth2/Server.php
index 02be4c5b..1c49b604 100644
--- a/src/Oauth2/Server.php
+++ b/src/Oauth2/Server.php
@@ -17,7 +17,7 @@ class Server
                 'code'
             ),
         'scope_delimeter'       =>  ',',
-        'access_token_expire'   =>  0
+        'access_token_ttl'   =>  null
     );
 
     public $exceptionCodes = array(