diff --git a/partner-masterpulsa-voucher.js b/partner-masterpulsa-voucher.js
index 308074b..d8d82dc 100644
--- a/partner-masterpulsa-voucher.js
+++ b/partner-masterpulsa-voucher.js
@@ -148,7 +148,8 @@ function getST24ResponseCode(supplierResponseCode) {
     if (['00', '13', '14', '47', '68'].indexOf(supplierResponseCode) >= 0) {
         st24rc = supplierResponseCode;
     }
-    else if (supplierResponseCode == '15') {
+    else if (['15', '56'].indexOf(supplierResponseCode) >= 0) {
+        // nomor tidak valid
         st24rc = '14';
     }
     else if (['05', '18', '63', '68'].indexOf(supplierResponseCode) >= 0) {