@@ -188,8 +188,14 @@ func (cli *Client) setupHijackConn(req *http.Request, proto string) (net.Conn, e

 	c, br := clientconn.Hijack()

 	if br.Buffered() > 0 {

-		// If there is buffered content, wrap the connection

-		c = &hijackedConn{c, br}

+		// If there is buffered content, wrap the connection.  We return an

+		// object that implements CloseWrite iff the underlying connection

+		// implements it.

+		if _, ok := c.(types.CloseWriter); ok {

+			c = &hijackedConnCloseWriter{c, br}

+		} else {

+			c = &hijackedConn{c, br}

+		}

 	} else {

 		br.Reset(nil)

 	}

@@ -197,6 +203,10 @@ func (cli *Client) setupHijackConn(req *http.Request, proto string) (net.Conn, e

 	return c, nil

 }

+// hijackedConn wraps a net.Conn and is returned by setupHijackConn in the case

+// that a) there was already buffered data in the http layer when Hijack() was

+// called, and b) the underlying net.Conn does *not* implement CloseWrite().

+// hijackedConn does not implement CloseWrite() either.

 type hijackedConn struct {

 	net.Conn

 	r *bufio.Reader

@@ -205,3 +215,16 @@ type hijackedConn struct {

 func (c *hijackedConn) Read(b []byte) (int, error) {

 	return c.r.Read(b)

 }

+

+// hijackedConnCloseWriter is a hijackedConn which additionally implements

+// CloseWrite().  It is returned by setupHijackConn in the case that a) there

+// was already buffered data in the http layer when Hijack() was called, and b)

+// the underlying net.Conn *does* implement CloseWrite().

+type hijackedConnCloseWriter hijackedConn

+

+var _ types.CloseWriter = &hijackedConnCloseWriter{}

+

+func (c *hijackedConnCloseWriter) CloseWrite() error {

+	conn := c.Conn.(types.CloseWriter)

+	return conn.CloseWrite()

+}