diff --git a/build/css.js b/build/build-css.js
similarity index 74%
rename from build/css.js
rename to build/build-css.js
index b1d2d4506..fabec32cf 100644
--- a/build/css.js
+++ b/build/build-css.js
@@ -1,36 +1,45 @@
-const postcssConfig = require('./postcss.config')
-const postcss = require('postcss')
-const glob = require('glob')
-const sass = require('node-sass')
-const cleancss = require('clean-css')
+'use strict'
+
 const fs = require('fs')
 const path = require('path')
-const files = ['bootstrap', 'bootstrap-grid', 'bootstrap-reboot', 'bootstrap-utilities']
+const postcss = require('postcss')
+const glob = require('glob')
+const sass = require('sass')
+const fiber = require('fibers')
+const Cleancss = require('clean-css')
+
+const postcssConfig = require('./postcss.config')
+
+const files = [
+  'bootstrap',
+  'bootstrap-grid',
+  'bootstrap-reboot',
+  'bootstrap-utilities'
+]
 
 files.forEach(filename => {
   sass.render({
     file: path.resolve(`./scss/${filename}.scss`),
+    fiber,
     outputStyle: 'expanded',
     sourceMap: true,
     sourceMapContents: true,
-    precision: 6,
     outFile: `./dist/css/${filename}.css`
   }, (error, css) => {
-    // Not sure what to do with css.map here
+    // Fix postcss to use and output sourcemaps
     postcss(postcssConfig)
       .process(css.css, { from: `./dist/css/${filename}.css` })
       .then(result => {
         fs.writeFile(`./dist/css/${filename}.css`, result.css, () => true)
-        fs.writeFile(`./dist/css/${filename}.min.css`, new cleancss().minify(result.css).styles, () => true)
+        fs.writeFile(`./dist/css/${filename}.min.css`, new Cleancss().minify(result.css).styles, () => true)
       })
   })
 })
 
-// Autoprefix examples
+// Prefix examples
 glob('./site/content/**/*.css', {}, (error, files) => {
   files.forEach(file => {
     fs.readFile(file, (err, css) => {
-
       postcss(postcssConfig)
         .process(css, { from: file, to: file })
         .then(result => {
diff --git a/package-lock.json b/package-lock.json
index 44f82765a..491ca2979 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3217,6 +3217,12 @@
       "integrity": "sha1-l4hXRCxEdJ5CBmE+N5RiBYJqvYA=",
       "dev": true
     },
+    "detect-libc": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/detect-libc/-/detect-libc-1.0.3.tgz",
+      "integrity": "sha1-+hN8S9aY7fVc1c0CrFWfkaTEups=",
+      "dev": true
+    },
     "di": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/di/-/di-0.0.1.tgz",
@@ -4415,6 +4421,15 @@
         "pend": "~1.2.0"
       }
     },
+    "fibers": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/fibers/-/fibers-5.0.0.tgz",
+      "integrity": "sha512-UpGv/YAZp7mhKHxDvC1tColrroGRX90sSvh8RMZV9leo+e5+EkRVgCEZPlmXeo3BUNQTZxUaVdLskq1Q2FyCPg==",
+      "dev": true,
+      "requires": {
+        "detect-libc": "^1.0.3"
+      }
+    },
     "figures": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/figures/-/figures-2.0.0.tgz",
diff --git a/package.json b/package.json
index f437c6c96..51a24a6bd 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
   "scripts": {
     "start": "npm-run-all --parallel watch docs-serve",
     "bundlewatch": "bundlewatch --config .bundlewatch.config.json",
-    "css": "node build/css.js",
+    "css": "node build/build-css.js",
     "css-rtl": "cross-env NODE_ENV=RTL postcss --config build/postcss.config.js --dir \"dist/css\" --ext \".rtl.css\" \"dist/css/*.css\" \"!dist/css/*.min.css\" \"!dist/css/*.rtl.css\"",
     "css-lint": "npm-run-all --continue-on-error --parallel css-lint-*",
     "css-lint-stylelint": "stylelint \"**/*.{css,scss}\" --cache --cache-location .cache/.stylelintcache --rd",
@@ -64,7 +64,7 @@
     "test": "npm-run-all lint dist js-test docs-build docs-lint",
     "netlify": "cross-env-shell HUGO_BASEURL=$DEPLOY_PRIME_URL npm-run-all dist release-sri docs-build",
     "watch": "npm-run-all --parallel watch-*",
-    "watch-css-main": "nodemon --watch scss/ --ext scss --exec \"npm-run-all css-lint css-compile css-prefix\"",
+    "watch-css-main": "nodemon --watch scss/ --ext scss --exec \"npm-run-all css-lint css\"",
     "watch-css-dist": "nodemon --watch dist/css/ --ext css --ignore \"dist/css/*.rtl.*\" --exec \"npm run css-rtl\"",
     "watch-css-docs": "nodemon --watch site/assets/scss/ --ext scss --exec \"npm run css-lint\"",
     "watch-js-main": "nodemon --watch js/src/ --ext js --exec \"npm-run-all js-lint js-compile\"",
@@ -107,6 +107,7 @@
     "eslint-config-xo": "^0.33.1",
     "eslint-plugin-import": "^2.22.1",
     "eslint-plugin-unicorn": "^25.0.0",
+    "fibers": "^5.0.0",
     "find-unused-sass-variables": "^3.0.0",
     "glob": "^7.1.6",
     "hammer-simulator": "0.0.1",