diff --git a/utils/helper.go b/utils/helper.go
index d9798ba..90f15cc 100644
--- a/utils/helper.go
+++ b/utils/helper.go
@@ -76,6 +76,9 @@ func MakeSign(obj interface{}, privateKey string) string {
 	var currentValue reflect.Value
 	for j := 0; j < keysCount; j++ {
 		currentKey = strings.ToLower(keys[j])
+		if currentKey == "sign" {
+			continue
+		}
 		currentValue = valueOfObj.FieldByName(keys[j])
 		str = fmt.Sprintf("%s%s=%v&", str, currentKey, currentValue)
 	}