Module build failed: ReferenceError: Promise is not defined

[Muhammed Niyazi Alpay]

When I enter the command line "npm run webpack" I give an error

fb-sleep-stats@0.9.0 webpack /root/fb-sleep-stats
webpack --progress

Hash: 4a711a63075eff90b928
Version: webpack 1.13.1
Time: 23234ms
Asset Size Chunks Chunk Names
bundle.js 2.3 MB 0 [emitted] main
+ 353 hidden modules

ERROR in .//css-loader!.//less-loader!./src/browser/components/main.less
Module build failed: ReferenceError: Promise is not defined
at LazyResult.async (/root/fb-sleep-stats/node_modules/css-loader/node_modules/postcss/lib/lazy-result.js:157:31)
at LazyResult.then (/root/fb-sleep-stats/node_modules/css-loader/node_modules/postcss/lib/lazy-result.js:79:21)
at processCss (/root/fb-sleep-stats/node_modules/css-loader/lib/processCss.js:198:5)
at Object.module.exports (/root/fb-sleep-stats/node_modules/css-loader/lib/loader.js:24:2)
@ ./src/browser/components/main.less 4:14-127

[Aleksandar Nakinov]

1. rm -rf node_modules/
2. set css-loader version to "^0.18.0" in package.json
3. npm install
4. npm run webpack

worked for me...