Socket.IO on client side

I am creating a nodejs+express+socket.io server.

Also I created a scaffold via yeoman for my frontend app.

The socket.io server is on port 3000 and my yeoman scaffold http server on 9000.

I have managed to retrieve the socket.io.js from the socket.io server using

<script type="text/javascript" src="http://localhost:3000/socket.io/socket.io.js"></script>

However im having this error:

GET http://localhost:9000/socket.io/?EIO=3&transport=polling&t=1425392110184-42 404 (Not Found) 

Why is the socket.io.js polling on port 9000? Moreover, how can I change this so that it'll poll on 3000 instead?