yep, [as commented here](https://gist.github.com/WebReflection/5593554#file-object-setprototypeof-js-L26) I could not find a way around IE < 11. 

About the fix, looks good to me but I wonder if the `&& Object.getPrototypeOf` is redundant?

P.S. if I wrote Opera was working, I probably was testing on Opera mobile, not Desktop. Please double check the broken behavior you mentioned is the same on mobile (not mini) and/or beta mobile.

Cheers