diff --git a/transport/transport.go b/transport/transport.go
index 82f5f09..d2319d0 100644
--- a/transport/transport.go
+++ b/transport/transport.go
@@ -4,6 +4,10 @@ import (
 	"net"
 )
 
+// Transport wraps and unwraps a proxy protocol frame on a net.Conn.
+// Wrap writes the protocol header (including target address) to the connection.
+// Unwrap reads and validates the protocol header, returning the target address.
+// Neither method closes the connection; the caller is responsible for that.
 type Transport interface {
 	Unwrap(conn net.Conn) (net.Addr, error)
 	Wrap(conn net.Conn, tgtHost string, tgtPort uint16) error
diff --git a/transport/transport_test.go b/transport/transport_test.go
index e0c3453..5756caa 100644
--- a/transport/transport_test.go
+++ b/transport/transport_test.go
@@ -2,10 +2,10 @@ package transport
 
 import (
 	"net"
-	"strings"
 	"testing"
 
 	"github.com/sower-proxy/conns/reread"
+	"github.com/sower-proxy/sower/transport/socks5"
 	"github.com/sower-proxy/sower/transport/sower"
 	"github.com/sower-proxy/sower/transport/trojan"
 )
@@ -22,14 +22,32 @@ func testPipe(tran Transport) (net.Addr, error) {
 	return tran.Unwrap(reread.New(r))
 }
 
+// testPipeDirect is like testPipe but passes the raw conn to Unwrap
+// (no reread wrapper), needed for transports where Unwrap writes back.
+func testPipeDirect(tran Transport) (net.Addr, error) {
+	r, w := net.Pipe()
+	defer r.Close()
+
+	go func(w net.Conn) {
+		defer w.Close()
+		tran.Wrap(w, "sower", 443)
+	}(w)
+
+	return tran.Unwrap(r)
+}
+
 func Test_Transports(t *testing.T) {
-	if addr, err := testPipe(newSower()); err != nil || strings.TrimSpace(addr.String()) != "sower:443" {
+	if addr, err := testPipe(newSower()); err != nil || addr.String() != "sower:443" {
 		t.Errorf("test sower, unexpected address: %s, err: %s", addr, err)
 	}
 
-	if addr, err := testPipe(newTrojan()); err != nil || strings.TrimSpace(addr.String()) != "sower:443" {
+	if addr, err := testPipe(newTrojan()); err != nil || addr.String() != "sower:443" {
 		t.Errorf("test trojan, unexpected address: %s, err: %s", addr, err)
 	}
+
+	if addr, err := testPipeDirect(socks5.New()); err != nil || addr.String() != "sower:443" {
+		t.Errorf("test socks5, unexpected address: %s, err: %s", addr, err)
+	}
 }
 
 func newSower() *sower.Sower {