Updated ionic for v2 now ionic emulate ios doesn't work

I’ve just updated the Ionic CLI for ionic 2 so I can start learning Ionic 2, but what I have found is that when I try to run a Ionic 1 app using ionic emulate ios I get this error message:

An error occurred trying to fall back to Cordova-lib execution: TypeError: Cannot read property ‘then’ of undefined

I think this is to do with the Cordova CLI version, but I’m not sure?