diff --git a/mempool/mempool_test.go b/mempool/mempool_test.go
index 9b57cfdb6..ad655c6df 100644
--- a/mempool/mempool_test.go
+++ b/mempool/mempool_test.go
@@ -9,7 +9,6 @@ import (
 	"github.com/tendermint/tendermint/proxy"
 	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tmsp/example/counter"
-	tmsp "github.com/tendermint/tmsp/types"
 )
 
 func init() {
@@ -70,10 +69,10 @@ func TestSerialReap(t *testing.T) {
 		for i := start; i < end; i++ {
 			txBytes := make([]byte, 8)
 			binary.BigEndian.PutUint64(txBytes, uint64(i))
-			code, result, logStr := appConnCon.AppendTx(txBytes)
-			if code != tmsp.CodeType_OK {
+			res := appConnCon.AppendTx(txBytes)
+			if !res.IsOK() {
 				t.Errorf("Error committing tx. Code:%v result:%X log:%v",
-					code, result, logStr)
+					res.Code, res.Data, res.Log)
 			}
 		}
 		hash, log := appConnCon.Commit()
diff --git a/proxy/local_app_conn.go b/proxy/local_app_conn.go
index 16edcaeb9..59ae33b52 100644
--- a/proxy/local_app_conn.go
+++ b/proxy/local_app_conn.go
@@ -54,21 +54,21 @@ func (app *localAppConn) SetOptionAsync(key string, value string) *tmspcli.ReqRe
 
 func (app *localAppConn) AppendTxAsync(tx []byte) *tmspcli.ReqRes {
 	app.mtx.Lock()
-	code, result, log := app.Application.AppendTx(tx)
+	res := app.Application.AppendTx(tx)
 	app.mtx.Unlock()
 	return app.callback(
 		tmsp.RequestAppendTx(tx),
-		tmsp.ResponseAppendTx(code, result, log),
+		tmsp.ResponseAppendTx(res.Code, res.Data, res.Log),
 	)
 }
 
 func (app *localAppConn) CheckTxAsync(tx []byte) *tmspcli.ReqRes {
 	app.mtx.Lock()
-	code, result, log := app.Application.CheckTx(tx)
+	res := app.Application.CheckTx(tx)
 	app.mtx.Unlock()
 	return app.callback(
 		tmsp.RequestCheckTx(tx),
-		tmsp.ResponseCheckTx(code, result, log),
+		tmsp.ResponseCheckTx(res.Code, res.Data, res.Log),
 	)
 }