diff --git a/sshmux.go b/sshmux.go
index c1c686b..d2ef6a8 100644
--- a/sshmux.go
+++ b/sshmux.go
@@ -32,8 +32,8 @@ type Server struct {
 	ProxyPolicy   ProxyPolicyConfig
 }
 
-type UpstreamInformation struct {
-	Host          string
+type upstreamInformation struct {
+	Address       string
 	Signer        ssh.Signer
 	Password      *string
 	ProxyProtocol byte
@@ -180,7 +180,7 @@ func (s *Server) handler(conn net.Conn) {
 func (s *Server) Handshake(session *ssh.PipeSession) error {
 	hasSetUser := false
 	var user string
-	var upstream *UpstreamInformation
+	var upstream *upstreamInformation
 	if s.Banner != "" {
 		err := session.Downstream.SendBanner(s.Banner)
 		if err != nil {
@@ -214,15 +214,11 @@ auth_requests:
 				if upstreamResp.Port == 0 {
 					upstreamResp.Port = 22
 				}
-				upstream = &UpstreamInformation{
+				upstream = &upstreamInformation{
 					Signer:   parsePrivateKey(upstreamResp.PrivateKey, upstreamResp.Certificate),
 					Password: upstreamResp.Password,
 				}
-				if host, err := netip.ParseAddr(upstreamResp.Host); err == nil {
-					upstream.Host = netip.AddrPortFrom(host, upstreamResp.Port).String()
-				} else {
-					upstream.Host = fmt.Sprintf("%s:%d", upstreamResp.Host, upstreamResp.Port)
-				}
+				upstream.Address = net.JoinHostPort(upstreamResp.Host, fmt.Sprintf("%d", upstreamResp.Port))
 				if upstreamResp.ProxyProtocol != nil {
 					switch *upstreamResp.ProxyProtocol {
 					case "v1":
@@ -270,7 +266,7 @@ auth_requests:
 		}
 	}
 	// Stage 2: connect to upstream
-	conn, err := net.Dial("tcp", upstream.Host)
+	conn, err := net.Dial("tcp", upstream.Address)
 	if err != nil {
 		return err
 	}
@@ -285,7 +281,7 @@ auth_requests:
 		User:            user,
 		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
 	}
-	err = session.InitUpstream(conn, upstream.Host, sshConfig)
+	err = session.InitUpstream(conn, upstream.Address, sshConfig)
 	if err != nil {
 		return err
 	}