diff --git a/wallet/v1/srv.proto b/wallet/v1/srv.proto
index 681e634..ca612db 100644
--- a/wallet/v1/srv.proto
+++ b/wallet/v1/srv.proto
@@ -27,7 +27,7 @@ service WalletService {
   rpc UserInitWallet(UserInitWalletReq) returns (base.v1.StatusRes);
   rpc UserGetWalletList(auth.v1.InternalIAM) returns (WalletList);
   rpc GetBalance(BalanceReq) returns (BalanceRes);
-  rpc CheckBalance(CheckBalanceReq) returns (base.v1.YesNoRes);
+  rpc CheckBalance(CheckBalanceReq) returns (base.v1.Empty); // Throws an error if balance is not enough
 
   rpc UserGetTransactionList(UserGetTransactionListReq) returns (TransactionList);