diff --git a/webapp/controller/ShopController.class.php b/webapp/controller/ShopController.class.php
index cb3e8bcc..55396dde 100644
--- a/webapp/controller/ShopController.class.php
+++ b/webapp/controller/ShopController.class.php
@@ -1712,7 +1712,7 @@ class ShopController extends BaseAuthedController
         return true;
     }
 
-    private function beginFirstTupop($address)
+    private function beginFirstTupop($address = null)
     {
         if (!$address) {
             $address = myself()->_getAddress();