diff --git a/server.go b/server.go
index de170830641..0251f48daf1 100644
--- a/server.go
+++ b/server.go
@@ -863,6 +863,7 @@ func (s *Server) handleRawConn(lisAddr string, rawConn net.Conn) {
 	// Finish handshaking (HTTP2)
 	st := s.newHTTP2Transport(conn, authInfo)
 	if st == nil {
+		conn.Close()
 		return
 	}