deprecate babel-preset-es2015@^6.18.0 We're super ???? excited that you're trying to use ES2015 syntax, but instead of continuing yearly presets ???? , we recommend using babel-preset-env: npm install babel-preset-env. preset-env without options will compile ES2015+ down to ES5. And by targeting specific browsers, Babel can do less work and you can ship native ES2015+ to users ???? ! Also, we are in the process of releasing v7, so give http://babeljs.io/blog/2017/09/12/planning-for-7.0 a read and test it! Thanks so much for using Babel ???? , please give us a follow @babeljs for updates, join slack.babeljs.io for discussion and help support at opencollective.com/babel