diff --git a/package.json b/package.json
index 22370b1706..58cb842ce8 100644
--- a/package.json
+++ b/package.json
@@ -136,6 +136,7 @@
     "modernizr": "^3.6.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "postcss-extend": "^1.0.5",
+    "postcss-hexrgba": "^2.0.0",
     "postcss-import": "^12.0.1",
     "postcss-loader": "^3.0.0",
     "postcss-mixins": "^6.2.3",
diff --git a/webpack.config.js b/webpack.config.js
index 9d8f333c87..d18f5649f0 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -182,6 +182,7 @@ module.exports = (env, argv) => {
 
                                     require("postcss-simple-vars")(),
                                     require("postcss-strip-inline-comments")(),
+                                    require("postcss-hexrgba")(),
 
                                     // It's important that this plugin is last otherwise we end
                                     // up with broken CSS.
@@ -219,6 +220,7 @@ module.exports = (env, argv) => {
                                     require("postcss-mixins")(),
                                     require("postcss-easings")(),
                                     require("postcss-strip-inline-comments")(),
+                                    require("postcss-hexrgba")(),
 
                                     // It's important that this plugin is last otherwise we end
                                     // up with broken CSS.
diff --git a/yarn.lock b/yarn.lock
index ad7be626ed..d6319cfecf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8964,6 +8964,13 @@ postcss-gap-properties@^2.0.0:
   dependencies:
     postcss "^7.0.2"
 
+postcss-hexrgba@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-hexrgba/-/postcss-hexrgba-2.0.0.tgz#1bdae7640047470b6935d8b0e5369f4acc987eb5"
+  integrity sha512-qZmURatbgathSg00kCAKG4h6iUwKnRbhMMWNN6V5u4NTKjuTplxi+CrhbHvQ8BNulTA4B51/RIWnNIoulJIDlg==
+  dependencies:
+    postcss "^7.0.14"
+
 postcss-html@^0.36.0:
   version "0.36.0"
   resolved "https://registry.yarnpkg.com/postcss-html/-/postcss-html-0.36.0.tgz#b40913f94eaacc2453fd30a1327ad6ee1f88b204"