How to make fish shell use an rvm ruby by default

I'm using fish shell 2.10 on Mac OS X 10.9.1. I would like to use a Ruby that I have installed using RVM as the default in my terminals, however I can't seem to make this work.

I've tried rvm use 2.1.0 --default but upon opening a new terminal I still get the following:

> which ruby/usr/bin/ruby

Running the rvm command causes the ruby to be loaded:

> which ruby/usr/bin/ruby> rvm[...]> which ruby/Users/alex/.rvm/rubies/ruby-2.1.0/bin/ruby

But it's annoying to have to do this every time I open a new terminal.