diff --git a/lib/callback/handler-postpaid.js b/lib/callback/handler-postpaid.js
index ae677df..8446e0c 100644
--- a/lib/callback/handler-postpaid.js
+++ b/lib/callback/handler-postpaid.js
@@ -64,5 +64,6 @@ module.exports = (req, res) => {
             },
         },
 
+        struk: struk || undefined,
     });
 };