diff --git a/benchmark_test.go b/benchmark_test.go
index 070df6c..5c09cac 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -2,6 +2,7 @@ package bidirpc
 
 import (
 	"net"
+	"net/rpc"
 	"testing"
 )
 
@@ -36,14 +37,23 @@ func (s *BenchService) EchoString(args StringArgs, reply *StringReply) error {
 var (
 	sessionYin  *Session
 	sessionYang *Session
+	client      *rpc.Client
+	server      *rpc.Server
 )
 
 func init() {
+	service := &BenchService{}
+
 	connYin, connYang := net.Pipe()
 	sessionYin, _ = NewSession(connYin, true)
 	sessionYang, _ = NewSession(connYang, false)
-	service := &BenchService{}
 	sessionYin.Register(service)
+
+	connServer, connClient := net.Pipe()
+	client = rpc.NewClient(connClient)
+	server = rpc.NewServer()
+	server.Register(service)
+	go server.ServeConn(connServer)
 }
 
 func BenchmarkEchoInt(b *testing.B) {
@@ -55,6 +65,15 @@ func BenchmarkEchoInt(b *testing.B) {
 	}
 }
 
+func BenchmarkBuiltinEchoInt(b *testing.B) {
+	args := IntArgs{}
+	reply := new(IntReply)
+	for i := 0; i < b.N; i++ {
+		args.V = int32(i)
+		client.Call("BenchService.EchoInt", args, reply)
+	}
+}
+
 func BenchmarkEchoString(b *testing.B) {
 	args := StringArgs{"abcdefghijklmnopqrstuvwxyz"}
 	reply := new(StringReply)
@@ -62,3 +81,11 @@ func BenchmarkEchoString(b *testing.B) {
 		sessionYang.Call("BenchService.EchoString", args, reply)
 	}
 }
+
+func BenchmarkBuiltinEchoString(b *testing.B) {
+	args := StringArgs{"abcdefghijklmnopqrstuvwxyz"}
+	reply := new(StringReply)
+	for i := 0; i < b.N; i++ {
+		client.Call("BenchService.EchoString", args, reply)
+	}
+}