diff --git a/Configuration/TCA/tx_mautic_domain_model_tag.php b/Configuration/TCA/tx_mautic_domain_model_tag.php
index 2a48617..4e7dcdc 100644
--- a/Configuration/TCA/tx_mautic_domain_model_tag.php
+++ b/Configuration/TCA/tx_mautic_domain_model_tag.php
@@ -16,7 +16,7 @@
             'default' => 'mimetypes-x-tx_marketingautomation_persona',
         ],
         'hideTable' => true,
-        'rootLevel' => true,
+        'rootLevel' => 1,
         'security' => [
             'ignoreRootLevelRestriction' => true,
         ],
diff --git a/README.md b/README.md
index a3e3b1e..5d1ac1c 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,20 @@ We currently support Mautic v4.
 * **For TYPO3 v10 and v11 on PHP7, please use extension release 4.3.x**
 * For TYPO3 v9, please use extension release 3.x
 
+## ⚠️ IMPORTANT
+> To install this extension on PHP 8 systems, you MUST add the following repository URL to your root `composer.json`:
+```json
+"repositories": [
+  {
+    "url": "https://github.com/Leuchtfeuer/api-library.git",
+    "type": "git"
+  }
+]
+ ```
+> Than install the extension by running `composer require mautic/mautic-typo3`.
+> The reason is that we have to use a forked version of `mautic/api-library` which is PHP 8 compatible, until an official
+> library version for PHP 8 is released (It should come with the release of Mautic 5).
+
 ## Features
 The Mautic TYPO3 extension has many features that allow you to integrate your marketing automation workflow in TYPO3.
 
@@ -87,3 +101,4 @@ You can contribute by making a pull request to the master branch of this reposit
 
 ## Questions or Suggestions?
 You can always open an issue in this repository if you find a bug or have a feature request. Next to that you can also come visit us on Slack ([Mautic](https://www.mautic.org/slack) or [TYPO3](https://typo3.org/article/how-to-use-slack-in-the-typo3-community/)> in the channel `#typo3-mautic`.
+
diff --git a/composer.json b/composer.json
index c6c2caa..62da911 100644
--- a/composer.json
+++ b/composer.json
@@ -25,11 +25,11 @@
         "docs": "https://docs.typo3.org/p/mautic/mautic-typo3/master/en-us/"
     },
     "require": {
-		"php": "<8.0",
-        "typo3/cms-core": "^10.4.2 || ^11.5",
-        "typo3/cms-extbase": "^10.4.2 || ^11.5",
+		"php": ">=8.0",
+        "typo3/cms-core": "^11.5",
+        "typo3/cms-extbase": "^11.5",
         "leuchtfeuer/marketing-automation": "^1.3",
-		"mautic/api-library": "^3.1"
+		"mautic/api-library": "^4.0"
     },
     "autoload": {
         "psr-4": {