diff --git a/src/OAuth2/AuthServer.php b/src/OAuth2/AuthServer.php
index d5af3650..97a46274 100644
--- a/src/OAuth2/AuthServer.php
+++ b/src/OAuth2/AuthServer.php
@@ -396,7 +396,7 @@ class AuthServer
      * @param  string $grantType The grant type identifer
      * @return class
      */
-    protected function getGrantType($grantType)
+    public function getGrantType($grantType)
     {
         return $this->grantTypes[$grantType];
     }