diff --git a/README.md b/README.md
index a557d760..e2b2bfe5 100644
--- a/README.md
+++ b/README.md
@@ -226,6 +226,15 @@ npm run build
 
 ## Upgrade Guide
 
+<details>
+<summary><strong>Upgrading from 8 to 9</strong></summary>
+
+1. Bump the version number in the `composer.json` file to `^9.0`.
+
+1. Copy the `public/mu-plugins/mu-plugins.php` file into your project.
+
+1. Run `composer update` in the root of your project and your app should be up and running!
+</details>
 <details>
 <summary><strong>Upgrading from 7 to 8</strong></summary>
 
@@ -407,7 +416,8 @@ If you or a company you work for use WordPlate, please consider buying a copy of
 WordPlate wouldn't be possible without these amazing open-source projects.
 
 - [`composer/installers`](https://github.com/composer/installers)
-- [`johnpbloch/wordpress`](https://github.com/johnpbloch/wordpress)
+- [`johnpbloch/wordpress-core`](https://github.com/johnpbloch/wordpress-core)
+- [`johnpbloch/wordpress-core-installer`](https://github.com/johnpbloch/wordpress-core-installer)
 - [`laravel-mix`](https://github.com/JeffreyWay/laravel-mix)
 - [`roots/bedrock-autoloader`](https://github.com/roots/bedrock-autoloader)
 - [`roots/wp-password-bcrypt`](https://github.com/roots/wp-password-bcrypt)
diff --git a/public/.gitignore b/public/.gitignore
index 1453237d..bf87a67b 100644
--- a/public/.gitignore
+++ b/public/.gitignore
@@ -1,5 +1,6 @@
 languages
-mu-plugins
+mu-plugins/*
+!mu-plugins/mu-plugins.php
 plugins/*
 !plugins/index.php
 upgrade
diff --git a/public/mu-plugins/mu-plugins.php b/public/mu-plugins/mu-plugins.php
new file mode 100644
index 00000000..3a7f7255
--- /dev/null
+++ b/public/mu-plugins/mu-plugins.php
@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * Plugin Name: Must Use Plugins
+ * Plugin URI: https://github.com/roots/bedrock-autoloader
+ * Description: Must-use plugins (a.k.a. mu-plugins) are plugins installed in a special directory inside the content folder and which are automatically enabled on all sites in the installation.
+ * Version: 1.0.0
+ * Author: Roots
+ * Author URI: https://roots.io/
+ * License: MIT
+ */
+
+if (is_blog_installed()) {
+    new Roots\Bedrock\Autoloader();
+}