diff --git a/docs/src/pages/migration/0.21.0.md b/docs/src/pages/migration/0.21.0.md
index bc3ce72a0..c61d04be7 100644
--- a/docs/src/pages/migration/0.21.0.md
+++ b/docs/src/pages/migration/0.21.0.md
@@ -186,5 +186,21 @@ To learn more about Vite plugins, please visit their [plugin guide](https://vite
 
 > In prior releases, these were configured with `snowpackPlugin` or `snowpackPluginOptions`.
 
+## Styling Changes
+
+### Autoprefixer
+
+Autoprefixer is no longer run by default. To enable:
+
+1. Install the latest version (`npm i autoprefixer`)
+2. Create a `postcss.config.cjs` file at the root of your project with:
+   ```js
+   module.exports = {
+     plugins: {
+       autoprefixer: {},
+     },
+   };
+   ```
+
 [snowpack]: https://www.snowpack.dev
 [vite]: https://vitejs.dev