From 22e3c699f682db9f54ba9c621babd2382e24c13a Mon Sep 17 00:00:00 2001
From: Paul Matthew Jaworski <53156002+pjaws@users.noreply.github.com>
Date: Fri, 17 Apr 2020 01:27:40 -0700
Subject: [PATCH] add warning about manually installing PostCSS plugins
 (#11966)

---
 docs/advanced-features/customizing-postcss-config.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/advanced-features/customizing-postcss-config.md b/docs/advanced-features/customizing-postcss-config.md
index 0b1cb7bbb2..2469cd9ff2 100644
--- a/docs/advanced-features/customizing-postcss-config.md
+++ b/docs/advanced-features/customizing-postcss-config.md
@@ -56,6 +56,7 @@ You can learn more about [Next.js' CSS Module support here](/docs/basic-features
 
 > **Warning**: When you define a custom PostCSS configuration file, Next.js **completely disables** the [default behavior](#default-behavior).
 > Be sure to manually configure all the features you need compiled, including [Autoprefixer](https://github.com/postcss/autoprefixer).
+> You also need to install any plugins included in your custom configuration manually, i.e. `npm install postcss-flexbugs-fixes`.
 
 To customize the PostCSS configuration, create a `postcss.config.json` file in the root of your project.