diff --git a/app/logic/Zone.php b/app/logic/Zone.php
index 4369bd6..11825e3 100644
--- a/app/logic/Zone.php
+++ b/app/logic/Zone.php
@@ -183,7 +183,7 @@ class Zone
      * @param $save_data
      * @return int|mixed
      */
-    protected static function calculateAmount($save_data)
+    protected static function calculateAmount(&$save_data)
     {
         $awards_amount = 0;
         foreach ($save_data as $key => $goodsParam) {