diff --git a/Classes/Domain/Renderer/Command.php b/Classes/Domain/Renderer/Command.php
index 00161cf..e4480e7 100644
--- a/Classes/Domain/Renderer/Command.php
+++ b/Classes/Domain/Renderer/Command.php
@@ -7,7 +7,7 @@ use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
 
 class Command implements RendererInterface
 {
-    public function getHtmlFromMjml($mjml)
+    public function getHtmlFromMjml($mjml): string
     {
         $conf = unserialize($GLOBALS['TYPO3_CONF_VARS']['EXT']['extConf']['mjml']);
 
@@ -36,7 +36,7 @@ class Command implements RendererInterface
      * @param string $args
      * @return string
      */
-    protected function getEscapedCommand(string $cmd, string $args)
+    protected function getEscapedCommand(string $cmd, string $args): string
     {
         $escapedCmd = escapeshellcmd($cmd);
 
diff --git a/Classes/Domain/Renderer/RendererInterface.php b/Classes/Domain/Renderer/RendererInterface.php
index 5cef1b2..a7b2673 100644
--- a/Classes/Domain/Renderer/RendererInterface.php
+++ b/Classes/Domain/Renderer/RendererInterface.php
@@ -12,5 +12,5 @@ interface RendererInterface
      * @param string $mjml
      * @return string
      */
-    public function getHtmlFromMjml($mjml);
+    public function getHtmlFromMjml($mjml): string;
 }
diff --git a/Classes/View/MjmlBasedView.php b/Classes/View/MjmlBasedView.php
index 116d33d..c8b2d45 100644
--- a/Classes/View/MjmlBasedView.php
+++ b/Classes/View/MjmlBasedView.php
@@ -7,10 +7,7 @@ use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
 
 class MjmlBasedView extends StandaloneView
 {
-    /**
-     * @var RendererInterface
-     */
-    protected $renderer;
+    protected RendererInterface $renderer;
 
     public function __construct(ContentObjectRenderer $contentObject = null, RendererInterface $renderer = null)
     {
@@ -22,7 +19,7 @@ class MjmlBasedView extends StandaloneView
         }
     }
 
-    public function render($actionName = null)
+    public function render($actionName = null): string
     {
         return $this->renderer->getHtmlFromMjml(parent::render($actionName));
     }
diff --git a/Tests/Unit/AbstractUnitTestCase.php b/Tests/Unit/AbstractUnitTestCase.php
index 814e944..4a4948a 100644
--- a/Tests/Unit/AbstractUnitTestCase.php
+++ b/Tests/Unit/AbstractUnitTestCase.php
@@ -8,7 +8,7 @@ use TYPO3\TestingFramework\Core\Unit\UnitTestCase;
 
 abstract class AbstractUnitTestCase extends UnitTestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
diff --git a/Tests/Unit/Domain/Renderer/CommandTest.php b/Tests/Unit/Domain/Renderer/CommandTest.php
index 0e0b794..5417195 100644
--- a/Tests/Unit/Domain/Renderer/CommandTest.php
+++ b/Tests/Unit/Domain/Renderer/CommandTest.php
@@ -11,12 +11,9 @@ use TYPO3\CMS\Extbase\Object\ObjectManager;
 
 class CommandTest extends AbstractUnitTestCase
 {
-    /**
-     * @var ObjectManager
-     */
-    protected $objectManager;
+    protected ObjectManager $objectManager;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->objectManager = GeneralUtility::makeInstance(ObjectManager::class);
@@ -25,7 +22,7 @@ class CommandTest extends AbstractUnitTestCase
     /**
      * @test
      */
-    public function htmlIsReturnedForMjml()
+    public function htmlIsReturnedForMjml(): void
     {
         // Mock extension to be active, to enable path fetching to call node binary.
         $packageMock = $this->getMockBuilder(Package::class)
diff --git a/Tests/Unit/View/MjmlBasedViewTest.php b/Tests/Unit/View/MjmlBasedViewTest.php
index 6d6b747..c5ba60b 100644
--- a/Tests/Unit/View/MjmlBasedViewTest.php
+++ b/Tests/Unit/View/MjmlBasedViewTest.php
@@ -31,7 +31,7 @@ class MjmlBasedViewTest extends AbstractUnitTestCase
     /**
      * @test
      */
-    public function viewCallsRendererAndReturnsRenderedHtml()
+    public function viewCallsRendererAndReturnsRenderedHtml(): void
     {
         $expectedHtml = '<h1>Simple HTML</h1>';
         $rendererMock = $this->getMockBuilder(RendererInterface::class)->getMock();
diff --git a/composer.json b/composer.json
index e90c524..dd336e7 100644
--- a/composer.json
+++ b/composer.json
@@ -15,9 +15,9 @@
         }
     },
     "require": {
-        "php": "^7.1",
-        "typo3/cms-core": "^8.7.0 || ^9.5.0 || ^10.4.0",
-        "typo3/cms-form": "^8.7.0 || ^9.5.0 || ^10.4.0"
+        "php": "^7.4",
+        "typo3/cms-core": "^9.5.0 || ^10.4.0",
+        "typo3/cms-form": "^9.5.0 || ^10.4.0"
     },
     "require-dev": {
         "squizlabs/php_codesniffer": "^3.2.0",
diff --git a/ext_emconf.php b/ext_emconf.php
index 6096e56..3bf1880 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -5,7 +5,7 @@ $EM_CONF[$_EXTKEY] = [
     'description' => 'Mjml view using mjml over npm',
     'category' => 'misc',
     'shy' => 0,
-    'version' => '1.0.6',
+    'version' => '2.0.0',
     'state' => 'stable',
     'clearCacheOnLoad' => 1,
     'author' => '',
@@ -17,8 +17,8 @@ $EM_CONF[$_EXTKEY] = [
         ],
     'constraints' => [
         'depends' => [
-            'php' => '7.1.0-7.3.99',
-            'typo3' => '8.7.0-9.5.99',
+            'php' => '7.4.0-7.4.99',
+            'typo3' => '9.5.17-10.9.99',
             'extbase' => '',
         ],
         'conflicts' => [