diff --git a/cmd/root.go b/cmd/root.go
index 18c8db3..c964a03 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -15,11 +15,12 @@ import (
 
 var flag struct {
 	//dnsServer    string
-	showsVersion bool
-	sshHost      string
-	sshPort      uint16
-	sshShell     string
-	sshUsers     []string
+	showsVersion  bool
+	sshHost       string
+	sshPort       uint16
+	sshUnixSocket string
+	sshShell      string
+	sshUsers      []string
 }
 
 type sshUser struct {
@@ -32,6 +33,8 @@ func init() {
 	RootCmd.PersistentFlags().BoolVarP(&flag.showsVersion, "version", "v", false, "show version")
 	RootCmd.PersistentFlags().StringVarP(&flag.sshHost, "host", "", "", "SSH server host (e.g. 127.0.0.1)")
 	RootCmd.PersistentFlags().Uint16VarP(&flag.sshPort, "port", "p", 2222, "SSH server port")
+	// NOTE: long name 'unix-socket' is from curl (ref: https://curl.se/docs/manpage.html)
+	RootCmd.PersistentFlags().StringVarP(&flag.sshUnixSocket, "unix-socket", "", "", "Unix-domain socket")
 	RootCmd.PersistentFlags().StringVarP(&flag.sshShell, "shell", "", "", "Shell")
 	//RootCmd.PersistentFlags().StringVar(&flag.dnsServer, "dns-server", "", "DNS server (e.g. 1.1.1.1:53)")
 	RootCmd.PersistentFlags().StringArrayVarP(&flag.sshUsers, "user", "", nil, `SSH user name (e.g. "john:mypassword")`)
@@ -90,13 +93,22 @@ var RootCmd = &cobra.Command{
 		}
 		sshConfig.AddHostKey(pri)
 
-		// TODO: unix socket support
-		address := net.JoinHostPort(flag.sshHost, strconv.Itoa(int(flag.sshPort)))
-		ln, err := net.Listen("tcp", address)
-		if err != nil {
-			return err
+		var ln net.Listener
+		if flag.sshUnixSocket == "" {
+			address := net.JoinHostPort(flag.sshHost, strconv.Itoa(int(flag.sshPort)))
+			ln, err = net.Listen("tcp", address)
+			if err != nil {
+				return err
+			}
+			logger.Info(fmt.Sprintf("listening on %s...", address))
+		} else {
+			ln, err = net.Listen("unix", flag.sshUnixSocket)
+			if err != nil {
+				return err
+			}
+			logger.Info(fmt.Sprintf("listening on %s...", flag.sshUnixSocket))
 		}
-		logger.Info(fmt.Sprintf("listening on %s...", address))
+		defer ln.Close()
 		for {
 			conn, err := ln.Accept()
 			if err != nil {