websocket example connection error

when attempting to follow the websocket client example at http://www.espruino.com/ws, i get errors on the server (running node.js on a windows10 laptop) as:

RangeError: Invalid WebSocket frame: RSV1 must be clear

When I modify the code to use the npm ws client on the laptop, it works fine.

server:
node 8.9.4,
"dependencies": {

"express": "^4.16.3",
"http": "0.0.0",
"url": "^0.11.0",
"ws": "^5.1.1"

}

espruino wifi client:
1v97

function wsConnect() {
    ws = new WebSocket(host, {path: '/', perMessageDeflate: false, port: 8080});
    ws.on('open', function() {
      // For WebSocket clients only
      console.log("Connected to server");
    });

    ws.on('message', function(msg) {
      console.log("MSG: " + msg);
    });

    ws.on('close', function() {
      console.log("Connection closed");
    });

    ws.on('handshake', function() {
      console.log("Handshake Success");
    });

    ws.on('ping', function() {
      console.log("Got a ping");
    });

    ws.on('pong', function() {
      console.log("Got a pong");
    });

    ws.on('rawData', function(msg) {
      console.log("RAW: " + msg);
    });
}

output on the repl is

wsConnect()
=undefined
RAW: HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: j5MohIRvl3Pm9AVPI+aTUTQIKxI=
Handshake Success
Connected to server
RAW:  something
MSG: something
RAW:  something
MSG: something
Connection closed
Connection closed