diff --git a/src/oauth2server/Server.php b/src/oauth2server/Server.php
index fee789fd..5b63e6b1 100644
--- a/src/oauth2server/Server.php
+++ b/src/oauth2server/Server.php
@@ -38,7 +38,7 @@ class Server
         maintenance of the server.'
     ); 
 
-    public function __construct(array $options)
+    public function __construct(array $options = null)
     {
         $this->options = array_merge($this->config, $options);
         if ($options !== null) {