diff --git a/index.js b/index.js
index c7cfde1..b065e49 100644
--- a/index.js
+++ b/index.js
@@ -65,8 +65,7 @@ function parseCss (src, filename, prefix, options, done) {
 
   applyTransforms(filename, String(src), Object.assign({}, options), function (err, result) {
     if (err) return done(err)
-    var p = postcss()
-    p = p.use(cssPrefix('.' + prefix))
+    var p = postcss([cssPrefix('.' + prefix)])
 
     try {
       result.css = p.process(result.css).toString()
diff --git a/package.json b/package.json
index 9c219bc..dfc46e0 100644
--- a/package.json
+++ b/package.json
@@ -32,8 +32,8 @@
     "fast-json-parse": "^1.0.2",
     "insert-css": "^2.0.0",
     "map-limit": "0.0.1",
-    "postcss": "^6.0.23",
-    "postcss-prefix": "^2.0.0",
+    "postcss": "^8.0.5",
+    "postcss-prefix": "^3.0.0",
     "resolve": "^1.1.7",
     "stack-trace": "0.0.10",
     "static-eval": "^2.0.0",