diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8fb88f9..201b109 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ on:
 
 jobs:
   testsuite:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
       matrix:
@@ -69,7 +69,7 @@ jobs:
 
   validation:
     name: Coding Standard & Static Analysis
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v1
diff --git a/README.md b/README.md
index aec0acb..8650247 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,17 @@
-[![CI](https://github.com/dereuromark/cakephp-whoops/workflows/CI/badge.svg?branch=master)](https://github.com/dereuromark/cakephp-whoops/actions?query=workflow%3ACI+branch%3Amaster) 
-[![Total Downloads](https://poser.pugx.org/dereuromark/cakephp-whoops/d/total.svg)](https://packagist.org/packages/dereuromark/cakephp-whoops) 
+# Whoops for CakePHP
+
+[![CI](https://github.com/dereuromark/cakephp-whoops/workflows/CI/badge.svg?branch=master)](https://github.com/dereuromark/cakephp-whoops/actions?query=workflow%3ACI+branch%3Amaster)
+[![Total Downloads](https://poser.pugx.org/dereuromark/cakephp-whoops/d/total.svg)](https://packagist.org/packages/dereuromark/cakephp-whoops)
 [![Latest Stable Version](https://poser.pugx.org/dereuromark/cakephp-whoops/v/stable.svg)](https://packagist.org/packages/dereuromark/cakephp-whoops)
-[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%207.2-8892BF.svg)](https://php.net/)
+[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%207.4-8892BF.svg)](https://php.net/)
 [![License](https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square)](https://packagist.org/packages/dereuromark/cakephp-whoops)
 
-# Whoops for CakePHP
-
 Seamlessly integrate [Whoops] into [CakePHP] applications.
 
 Demo-Video: [Linux Mint + Firefox](https://streamable.com/s/h63t3/xweicf)
 
+This branch is for use with **CakePHP 4.2+**. For details see [version map](https://github.com/dereuromark/cakephp-whoops/wiki#cakephp-version-map).
+
 ## Install
 
 Using [Composer]:
diff --git a/composer.json b/composer.json
index 23d2994..b0d5fcf 100644
--- a/composer.json
+++ b/composer.json
@@ -26,8 +26,8 @@
 		"source": "https://github.com/dereuromark/cakephp-whoops"
 	},
 	"require": {
-		"php": ">=7.2",
-		"cakephp/cakephp": "^4.0",
+		"php": ">=7.4",
+		"cakephp/cakephp": "^4.2",
 		"filp/whoops": "^2.0"
 	},
 	"require-dev": {
@@ -45,10 +45,10 @@
 	},
 	"scripts": {
 		"test": "php phpunit.phar",
-		"test-setup": "[ ! -f phpunit.phar ] && wget https://phar.phpunit.de/phpunit-8.5.13.phar && mv phpunit-8.5.13.phar phpunit.phar || true",
+		"test-setup": "[ ! -f phpunit.phar ] && wget https://phar.phpunit.de/phpunit-9.5.13.phar && mv phpunit-9.5.13.phar phpunit.phar || true",
 		"test-coverage" : "php phpunit.phar --log-junit tmp/coverage/unitreport.xml --coverage-html tmp/coverage --coverage-clover tmp/coverage/coverage.xml",
 		"stan": "phpstan analyse",
-		"stan-setup": "cp composer.json composer.backup && composer require --dev phpstan/phpstan:^0.12 && mv composer.backup composer.json",
+		"stan-setup": "cp composer.json composer.backup && composer require --dev phpstan/phpstan:^1.0.0 && mv composer.backup composer.json",
 		"cs-check": "phpcs -p --standard=vendor/fig-r/psr2r-sniffer/PSR2R/ruleset.xml --extensions=php src/ tests/",
 		"cs-fix": "phpcbf -v --standard=vendor/fig-r/psr2r-sniffer/PSR2R/ruleset.xml --extensions=php src/ tests/"
 	},
diff --git a/src/Error/Middleware/WhoopsHandlerMiddleware.php b/src/Error/Middleware/WhoopsHandlerMiddleware.php
index 341448e..a032238 100644
--- a/src/Error/Middleware/WhoopsHandlerMiddleware.php
+++ b/src/Error/Middleware/WhoopsHandlerMiddleware.php
@@ -20,6 +20,9 @@ class WhoopsHandlerMiddleware extends ErrorHandlerMiddleware {
 
 	use WhoopsTrait;
 
+	/**
+	 * @var string
+	 */
 	public const PHP_SAPI_CLI = 'cli';
 
 	/**
diff --git a/src/Error/WhoopsHandler.php b/src/Error/WhoopsHandler.php
index ce17095..e62d614 100644
--- a/src/Error/WhoopsHandler.php
+++ b/src/Error/WhoopsHandler.php
@@ -3,7 +3,7 @@
 namespace CakephpWhoops\Error;
 
 use Cake\Core\Configure;
-use Cake\Core\Exception\Exception as CakeException;
+use Cake\Core\Exception\CakeException;
 use Cake\Error\ErrorHandler;
 use Cake\Http\ServerRequest;
 use Cake\Routing\Router;
diff --git a/src/Error/WhoopsTrait.php b/src/Error/WhoopsTrait.php
index 5d9226e..d5d6b4f 100644
--- a/src/Error/WhoopsTrait.php
+++ b/src/Error/WhoopsTrait.php
@@ -10,7 +10,7 @@
 trait WhoopsTrait {
 
 	/**
-	 * @var \Whoops\Run
+	 * @var \Whoops\Run|null
 	 */
 	protected $_whoops;
 
@@ -18,7 +18,7 @@ trait WhoopsTrait {
 	 * @return \Whoops\Run
 	 */
 	protected function getWhoopsInstance(): Run {
-		if (empty($this->_whoops)) {
+		if ($this->_whoops === null) {
 			$this->_whoops = new Run();
 		}