VSCode Jupyter Notebook - can't change remote kernel

I have a jupyter notebook server running on a remote machine and I would like to use VScode to work on it. The remote server can be accessed over an ssh tunnel like so:

ssh -N -f -L localhost:8888:localhost:8888 user@server-ip

The VScode connects to this server when I set the Jupyter Server URI but it connected to the python 2.7 kernel. How do I make it use the python 3.5 kernel? Thanks.