diff --git a/packages/calypso-build/package.json b/packages/calypso-build/package.json
index ae1b6bfc0a64f..6aaa6d8077e7c 100644
--- a/packages/calypso-build/package.json
+++ b/packages/calypso-build/package.json
@@ -46,12 +46,12 @@
 		"@wordpress/babel-plugin-import-jsx-pragma": "2.3.0",
 		"@wordpress/browserslist-config": "2.3.0",
 		"@wordpress/dependency-extraction-webpack-plugin": "1.1.0",
-		"autoprefixer": "9.4.4",
+		"autoprefixer": "10.0.0",
 		"babel-jest": "^24.9.0",
 		"babel-loader": "8.0.5",
 		"browserslist": "4.6.6",
 		"caniuse-api": "3.0.0",
-		"css-loader": "2.1.1",
+		"css-loader": "5.0.0",
 		"duplicate-package-checker-webpack-plugin": "3.0.0",
 		"enzyme": "3.10.0",
 		"enzyme-adapter-react-16": "1.14.0",
@@ -60,8 +60,8 @@
 		"jest-config": "24.9.0",
 		"mini-css-extract-plugin-with-rtl": "github:Automattic/mini-css-extract-plugin-with-rtl#v0.7.0-with-rtl",
 		"node-sass": "4.11.0",
-		"postcss-custom-properties": "8.0.9",
-		"postcss-loader": "3.0.0",
+		"postcss-custom-properties": "11.0.0",
+		"postcss-loader": "4.0.0",
 		"recursive-copy": "2.0.10",
 		"sass-loader": "7.1.0",
 		"terser-webpack-plugin": "1.2.3",