Socket.io on elastic beanstalk error

I get an error

http://lowcost-env.b8cgexs3tc.us-west-2.elasticbeanstalk.com/socket.io/?EIO=3&transport=polling&t=LliRJNu 404 (Not Found)

when I have deployed my app and try to run it. Socket.io works great locally on localhost.

My server-setup:

var server = require('http').Server(express);
var io = require('socket.io')(server);
var activeMatches = [];

server.listen(8080); 

Client:

   io.connect('LowCost-env.b8cgexs3tc.us-west-2.elasticbeanstalk.com')

In Amazon I have disabled proxy so I'm not using nginx. Whats the problem here?

via KimR