diff --git a/.github/workflows/test-application.yaml b/.github/workflows/test-application.yaml
index 64ab2b95..c7022446 100644
--- a/.github/workflows/test-application.yaml
+++ b/.github/workflows/test-application.yaml
@@ -20,6 +20,7 @@ jobs:
                       database: postgres
                       dependency-versions: 'lowest'
                       tools: 'composer:v2'
+                      phpunit-config: 'phpunit-9.xml.dist'
                       env:
                           SYMFONY_DEPRECATIONS_HELPER: disabled
                           DATABASE_URL: postgres://postgres:postgres@127.0.0.1/sulu_form_test?serverVersion=12.5
@@ -30,6 +31,7 @@ jobs:
                       database: mysql
                       dependency-versions: 'highest'
                       tools: 'composer:v2'
+                      phpunit-config: 'phpunit-9.xml.dist'
                       env:
                           SYMFONY_DEPRECATIONS_HELPER: weak
                           DATABASE_URL: mysql://root:root@127.0.0.1/sulu_form_test?serverVersion=5.7
@@ -57,6 +59,16 @@ jobs:
                           DATABASE_COLLATE: utf8mb4_unicode_ci
 
                     - php-version: '8.2'
+                      database: postgres
+                      dependency-versions: 'highest'
+                      tools: 'composer:v2'
+                      env:
+                          SYMFONY_DEPRECATIONS_HELPER: weak
+                          DATABASE_URL: postgres://postgres:postgres@127.0.0.1/sulu_form_test?serverVersion=12.5
+                          DATABASE_CHARSET: UTF8
+                          DATABASE_COLLATE:
+
+                    - php-version: '8.3'
                       database: mysql
                       dependency-versions: 'highest'
                       tools: 'composer:v2'
@@ -66,10 +78,11 @@ jobs:
                           DATABASE_CHARSET: utf8mb4
                           DATABASE_COLLATE: utf8mb4_unicode_ci
 
-                    - php-version: '8.3'
+                    - php-version: '8.4'
                       database: mysql
                       dependency-versions: 'highest'
                       tools: 'composer:v2'
+                      composer-options: '--ignore-platform-reqs'
                       env:
                           SYMFONY_DEPRECATIONS_HELPER: weak
                           DATABASE_URL: mysql://root:root@127.0.0.1/sulu_form_test?serverVersion=5.7
@@ -96,7 +109,7 @@ jobs:
 
         steps:
             - name: Checkout project
-              uses: actions/checkout@v2
+              uses: actions/checkout@v4
 
             - name: Install and configure PHP
               uses: shivammathur/setup-php@v2
@@ -106,11 +119,13 @@ jobs:
                   tools: ${{ matrix.tools }}
                   coverage: none
 
-            - name: Remove not required tooling for tests
-              run: composer remove php-cs-fixer/shim "*phpstan*" --dev --no-update
+            - name: Remove Lint Tools
+              # These tools are not required to run tests, so we are removing them to improve dependency resolving and
+              # testing lowest versions.
+              run: composer remove "*php-cs-fixer*" "*phpstan*" "*rector*" --dev --no-update
 
             - name: Install composer dependencies
-              uses: ramsey/composer-install@v1
+              uses: ramsey/composer-install@v2
               with:
                   dependency-versions: ${{matrix.dependency-versions}}
                   composer-options: ${{ matrix.composer-options }}
@@ -120,7 +135,7 @@ jobs:
               env: ${{ matrix.env }}
 
             - name: Execute test cases
-              run: time composer test
+              run: time composer test -- --config ${{ matrix.phpunit-config || 'phpunit.xml.dist' }}
               env: ${{ matrix.env }}
 
     lint:
@@ -131,7 +146,7 @@ jobs:
 
         steps:
             - name: Checkout project
-              uses: actions/checkout@v2
+              uses: actions/checkout@v4
 
             - name: Install and configure PHP
               uses: shivammathur/setup-php@v2
@@ -142,7 +157,7 @@ jobs:
                   coverage: none
 
             - name: Install composer dependencies
-              uses: ramsey/composer-install@v1
+              uses: ramsey/composer-install@v2
               with:
                   dependency-versions: ${{matrix.dependency-versions}}
                   composer-options: ${{ matrix.composer-options }}
diff --git a/Tests/Functional/Mail/HelperTestCase.php b/Tests/Functional/Mail/HelperTestCase.php
index 84da9504..a6ab71f6 100644
--- a/Tests/Functional/Mail/HelperTestCase.php
+++ b/Tests/Functional/Mail/HelperTestCase.php
@@ -33,8 +33,6 @@ class HelperTestCase extends SuluTestCase
 
     protected function setUp(): void
     {
-        static::$kernel = null; // requires as Symfony 4.4 does not unset on tearDown
-
         $this->client = $this->createWebsiteClient();
         $this->purgeDatabase();
         $this->initPhpcr();
diff --git a/composer.json b/composer.json
index edff35e5..a61ef1b7 100644
--- a/composer.json
+++ b/composer.json
@@ -49,7 +49,7 @@
         "phpstan/phpstan-doctrine": "^1.0",
         "phpstan/phpstan-phpunit": "^1.0",
         "phpstan/phpstan-symfony": "^1.0",
-        "phpunit/phpunit": "^8.0",
+        "phpunit/phpunit": "^9.6 || ^10.0",
         "sendinblue/api-v3-sdk": "^8.0",
         "symfony/browser-kit": "^4.4 || ^5.0 || ^6.0 || ^7.0",
         "symfony/dotenv": "^4.4 || ^5.0 || ^6.0 || ^7.0",
diff --git a/phpunit-9.xml.dist b/phpunit-9.xml.dist
new file mode 100644
index 00000000..0e62f3be
--- /dev/null
+++ b/phpunit-9.xml.dist
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit colors="true" bootstrap="Tests/test-bootstrap.php">
+   <testsuites>
+        <testsuite name="Sulu Form Bundle">
+            <directory>./Tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist addUncoveredFilesFromWhitelist="true">
+            <directory>.</directory>
+            <exclude>
+                <directory>Resources/</directory>
+                <directory>Tests/</directory>
+                <directory>vendor/</directory>
+            </exclude>
+        </whitelist>
+    </filter>
+
+    <php>
+        <env name="KERNEL_CLASS" value="Sulu\Bundle\FormBundle\Tests\Application\Kernel"/>
+        <env name="APP_ENV" value="test" force="true"/>
+    </php>
+</phpunit>
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index bbaf9804..f355e585 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,25 +1,24 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit colors="true" bootstrap="Tests/test-bootstrap.php">
-   <testsuites>
+    <testsuites>
         <testsuite name="Sulu Form Bundle">
             <directory>./Tests</directory>
         </testsuite>
     </testsuites>
 
-    <filter>
-        <whitelist addUncoveredFilesFromWhitelist="true">
-            <directory>.</directory>
-            <exclude>
-                <directory>Resources/</directory>
-                <directory>Tests/</directory>
-                <directory>vendor/</directory>
-            </exclude>
-        </whitelist>
-    </filter>
-
     <php>
         <env name="KERNEL_CLASS" value="Sulu\Bundle\FormBundle\Tests\Application\Kernel"/>
         <env name="APP_ENV" value="test" force="true"/>
-        <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak"/>
     </php>
+
+    <source>
+        <include>
+            <directory>./</directory>
+        </include>
+        <exclude>
+            <directory>Resources/</directory>
+            <directory>Tests/</directory>
+            <directory>vendor/</directory>
+        </exclude>
+    </source>
 </phpunit>