diff --git a/README.md b/README.md
index 33ca367..ffd3a8a 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ This plugin allows you to add an email contact form to your website.
 
 ## Requirements
 
-This plugin requires Craft CMS 4.0.0+ or 5.0.0+.
+This plugin requires Craft CMS 4.0.0+ or 5.0.0+ or 6.0.0-alpha.1+ with the `craftcms/yii2-adapter` package.
 
 ## Installation
 
@@ -169,7 +169,7 @@ return [
 
 ### Overriding plugin settings
 
-If you create a [config file](https://craftcms.com/docs/4.x/config/) in your `config/` folder called `contact-form.php`, you can override
+If you create a [config file](https://craftcms.com/docs/4.x/config/) in your `config/` folder (or `config/craft/` if you’re using Craft CMS v6) called `contact-form.php`, you can override
 the plugin’s settings in the Control Panel.  Since that config file is fully [multi-environment](https://craftcms.com/docs/4.x/config/#multi-environment-configs) aware, this is
 a handy way to have different settings across multiple environments.
 
diff --git a/composer.json b/composer.json
index 5f84523..d29e1f5 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,7 @@
   "prefer-stable": true,
   "require": {
     "php": "^8.0.2",
-    "craftcms/cms": "^4.0.0-beta.1|^5.0.0-beta.1"
+    "craftcms/cms": "^4.0.0-beta.1|^5.0.0-beta.1|^6.0.0-alpha.1"
   },
   "require-dev": {
     "craftcms/ecs": "dev-main",
diff --git a/src/models/Submission.php b/src/models/Submission.php
index 2384974..19f39b3 100644
--- a/src/models/Submission.php
+++ b/src/models/Submission.php
@@ -47,7 +47,7 @@ class Submission extends Model
     /**
      * @inheritdoc
      */
-    public function attributeLabels()
+    public function attributeLabels(): array
     {
         return [
             'fromName' => \Craft::t('contact-form', 'Your Name'),