diff --git a/userguide/package.json b/userguide/package.json
index 5f1ec6ab17..a1fc669d2a 100644
--- a/userguide/package.json
+++ b/userguide/package.json
@@ -18,7 +18,7 @@
   "homepage": "https://github.com/google#readme",
   "dependencies": {},
   "devDependencies": {
-    "autoprefixer": "^9.5.0",
-    "postcss-cli": "^5.0.1"
+    "autoprefixer": "^10.0.0",
+    "postcss-cli": "^8.0.0"
   }
 }