diff --git a/webapp/controller/ShopController.class.php b/webapp/controller/ShopController.class.php
index f788b20b..d59c0be1 100644
--- a/webapp/controller/ShopController.class.php
+++ b/webapp/controller/ShopController.class.php
@@ -1289,7 +1289,7 @@ class ShopController extends BaseAuthedController
         }
 
         $num = $box['item_num'];
-        if ($num <= 1) {
+        if ($num < 1) {
             $this->_rspErr(2, 'num is invalid');
             return;
         }