diff --git a/cmd/frpc/sub/stcp.go b/cmd/frpc/sub/stcp.go
index 45229a0..d3a5d4a 100644
--- a/cmd/frpc/sub/stcp.go
+++ b/cmd/frpc/sub/stcp.go
@@ -39,7 +39,7 @@ func init() {
 	stcpCmd.PersistentFlags().StringVarP(&serverName, "server_name", "", "", "server name")
 	stcpCmd.PersistentFlags().StringVarP(&localIp, "local_ip", "i", "127.0.0.1", "local ip")
 	stcpCmd.PersistentFlags().IntVarP(&localPort, "local_port", "l", 0, "local port")
-	stcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr")
+	stcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr such as 127.0.0.1:9000")
 	stcpCmd.PersistentFlags().BoolVarP(&useEncryption, "ue", "", false, "use encryption")
 	stcpCmd.PersistentFlags().BoolVarP(&useCompression, "uc", "", false, "use compression")
 
diff --git a/cmd/frpc/sub/xtcp.go b/cmd/frpc/sub/xtcp.go
index 09ea892..e7d0752 100644
--- a/cmd/frpc/sub/xtcp.go
+++ b/cmd/frpc/sub/xtcp.go
@@ -39,7 +39,7 @@ func init() {
 	xtcpCmd.PersistentFlags().StringVarP(&serverName, "server_name", "", "", "server name")
 	xtcpCmd.PersistentFlags().StringVarP(&localIp, "local_ip", "i", "127.0.0.1", "local ip")
 	xtcpCmd.PersistentFlags().IntVarP(&localPort, "local_port", "l", 0, "local port")
-	xtcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr")
+	xtcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr such as 127.0.0.1:9000")
 	xtcpCmd.PersistentFlags().BoolVarP(&useEncryption, "ue", "", false, "use encryption")
 	xtcpCmd.PersistentFlags().BoolVarP(&useCompression, "uc", "", false, "use compression")