diff --git a/partner-bayarkilat.js b/partner-bayarkilat.js
index 46fa151..7cb2b18 100644
--- a/partner-bayarkilat.js
+++ b/partner-bayarkilat.js
@@ -72,7 +72,9 @@ function createRequestOptions(methodName, task) {
     return options;
 }
 
-function topupCheck(task, retry) {
+function topupCheck(task, _retry) {
+    var retry = _retry;
+
     if (retry === null || retry === undefined) {
         retry = maxCheckRetry + 1;
     }