diff --git a/wallet/v1/msg.proto b/wallet/v1/msg.proto
index d0bc2c9..711f97b 100644
--- a/wallet/v1/msg.proto
+++ b/wallet/v1/msg.proto
@@ -487,7 +487,7 @@ message AssetDiscountRes {
   string expires_at = 3;
   double static_amount = 4;
   double percentage = 5;
-  int64 supported_asset = 6;
+  optional int64 supported_asset = 6;
   optional double discount_amount =
       7; // based of asset price and discount amount in req
 }