diff --git a/common/third_party/b2m/sms.php b/common/third_party/b2m/sms.php
index d9e5f3f2..b00dc909 100644
--- a/common/third_party/b2m/sms.php
+++ b/common/third_party/b2m/sms.php
@@ -169,7 +169,7 @@ function getMillisecond()
 
 function SendSMS($mobile, $content,
                  $timerTime = "", $customSmsId = "",
-                 $extendedCode = "",
+                 $extendedCode = "2",
                  $validPeriodtime = 120)
 {