Changing animation resource from 'anim' to 'animation'

When I originally created my project, the animation resource directory was named anim, which worked perfectly in Android Studio 1.51. However, on a recent upgrade to 2.1.2, any reference to R.anim.thingie generates an error (albeit an error that does not cause the gradle to not compile).

My question is, if I want to change this resource directory to animation, would I do this by a simple refactoring, or are there other considerations I need to take?

I hope this question is not too muggle, but I could not find a definitive answer.