Create-react-app: IE 11 'Symbol is undefined'

[rockmandash]

My win 7 ie 11 complains 'Symbol' is undefined.
Object.keys won't work too.
I have to do this
import 'core-js/es6/symbol;
import 'core-js/fn/symbol/iterator;
at very top of index.js.

It would be wonderful with default support >/////<
Thank you !

[milesrichardson]

You need a polyfill. I'm using babel-polyfill with success.

It should be as simple as including import "babel-polyfill" at the top of index.js

[rockmandash]

SODESUGA！
Thank you very much！