diff --git a/src/Zarinpal.php b/src/Zarinpal.php
index 4c60a5d..347ce88 100644
--- a/src/Zarinpal.php
+++ b/src/Zarinpal.php
@@ -7,7 +7,7 @@
 
 class Zarinpal
 {
-    private $redirectUrl = 'https://www.zarinpal.com/pg/StartPay/%u';
+    private $redirectUrl = 'https://www.zarinpal.com/pg/StartPay/%s';
     private $merchantID;
     private $driver;
     private $Authority;