diff --git a/lib/partner-listener/routers/topup.js b/lib/partner-listener/routers/topup.js
index 10b1ded..eb02f9d 100644
--- a/lib/partner-listener/routers/topup.js
+++ b/lib/partner-listener/routers/topup.js
@@ -101,8 +101,8 @@ async function pageIndex(req, res) {
         destination: coreResponse.destination,
         rc: coreResponse.rc,
         sn: coreResponse.sn,
-        amount: Number(coreResponse.amount) || null,
-        ending_balance: Number(coreResponse.ending_balance) || null,
+        amount: Number(coreResponse.amount) || undefined,
+        ending_balance: Number(coreResponse.ending_balance) || undefined,
         message: coreResponse.message,
     };