diff --git a/client.go b/client.go
index e11a174..b14e891 100644
--- a/client.go
+++ b/client.go
@@ -17,7 +17,7 @@ type Client struct {
 	sshConn   ssh.Conn
 	client    *ssh.Client
 	listeners []net.Listener
-	ch        chan int
+	ch        chan struct{}
 }
 
 // NewClient create a new ssh Client
@@ -51,7 +51,7 @@ func NewClient(c net.Conn, config *ssh.ClientConfig, addr string, conf *Conf) (*
 	sshClient := ssh.NewClient(sshConn, newch, reqs)
 	client := &Client{
 		conn: c, sshConn: sshConn, client: sshClient,
-		ch: make(chan int),
+		ch: make(chan struct{}),
 	}
 	go client.keepAlive(conf.KeepAliveInterval, conf.KeepAliveMax)
 	return client, nil
@@ -74,7 +74,7 @@ func (cc *Client) Run() {
 		go func() {
 			cc.sshConn.Wait()
 			select {
-			case cc.ch <- 1:
+			case cc.ch <- struct{}{}:
 			default:
 			}
 		}()
@@ -305,7 +305,7 @@ func (cc *Client) keepAlive(interval time.Duration, maxCount int) {
 				cc.sshConn.Close()
 				// send exit signal
 				select {
-				case cc.ch <- 1:
+				case cc.ch <- struct{}{}:
 				default:
 				}
 				return
@@ -321,7 +321,7 @@ func (cc *Client) registerSignal() {
 	case s1 := <-c:
 		Log(ERROR, "signal %d received, exit", s1)
 		select {
-		case cc.ch <- 1:
+		case cc.ch <- struct{}{}:
 		default:
 		}
 	}
diff --git a/server.go b/server.go
index 8f0d45f..6b41280 100644
--- a/server.go
+++ b/server.go
@@ -12,7 +12,7 @@ type Server struct {
 	conn           net.Conn
 	sshConn        *ssh.ServerConn
 	forwardedPorts map[string]net.Listener
-	exitCh         chan int
+	exitCh         chan struct{}
 }
 
 // NewServer create a new struct for Server
@@ -47,7 +47,7 @@ func NewServer(c net.Conn, config *ssh.ServerConfig, conf *Conf) (*Server, error
 	sc := &Server{conn: c,
 		sshConn:        sshConn,
 		forwardedPorts: map[string]net.Listener{},
-		exitCh:         make(chan int)}
+		exitCh:         make(chan struct{})}
 	go sc.handleGlobalRequest(req)
 	go sc.handleNewChannelRequest(ch)
 	return sc, nil
diff --git a/util.go b/util.go
index b8fce2b..65f47f5 100644
--- a/util.go
+++ b/util.go
@@ -22,16 +22,16 @@ var SSHLogLevel = ERROR
 func PipeAndClose(c io.ReadWriteCloser, s io.ReadWriteCloser) {
 	defer c.Close()
 	defer s.Close()
-	cc := make(chan int, 2)
+	cc := make(chan struct{}, 2)
 
 	go func() {
 		io.Copy(c, s)
-		cc <- 1
+		cc <- struct{}{}
 	}()
 
 	go func() {
 		io.Copy(s, c)
-		cc <- 1
+		cc <- struct{}{}
 	}()
 
 	<-cc