diff --git a/Classes/ViewHelpers/PurifyViewHelper.php b/Classes/ViewHelpers/PurifyViewHelper.php
index 4a42ef0..fcd1cfd 100644
--- a/Classes/ViewHelpers/PurifyViewHelper.php
+++ b/Classes/ViewHelpers/PurifyViewHelper.php
@@ -10,6 +10,7 @@
  * LICENSE.txt file that was distributed with this source code.
  */
 
+use TYPO3\CMS\Extbase\Configuration\ConfigurationManager;
 use ElementareTeilchen\HtmlPurify\Service\PurifyService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface;
@@ -91,7 +92,7 @@ public static function renderStatic(
 
         // use typoscript default values if configured
         } else {
-            $configurationManager = GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Configuration\\ConfigurationManager');
+            $configurationManager = GeneralUtility::makeInstance(ConfigurationManager::class);
             $typoScript = $configurationManager->getConfiguration(
                 ConfigurationManagerInterface::CONFIGURATION_TYPE_SETTINGS,
                 'html_purify'
diff --git a/Configuration/TCA/Overrides/sys_template.php b/Configuration/TCA/Overrides/sys_template.php
index ee53349..5a902b7 100644
--- a/Configuration/TCA/Overrides/sys_template.php
+++ b/Configuration/TCA/Overrides/sys_template.php
@@ -1,4 +1,4 @@
 <?php
-defined('TYPO3_MODE') or die();
+defined('TYPO3') or die();
 
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile('html_purify', 'Configuration/TypoScript', 'HTML purify');
diff --git a/composer.json b/composer.json
index 7bc1744..5fb393d 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
 		"GPL-2.0+"
 	],
 	"require": {
-		"typo3/cms-core": "^10.4 || ^11.5",
+		"typo3/cms-core": "^11.5 || ^12.4",
 		"ezyang/htmlpurifier": "^4.17"
 	},
 	"autoload": {
diff --git a/ext_emconf.php b/ext_emconf.php
index 8938bb5..3c984c0 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -1,23 +1,17 @@
 <?php
-$EM_CONF[$_EXTKEY] = array(
+$EM_CONF[$_EXTKEY] = [
     'title' => 'HTML pruify',
     'description' => 'Adds HTML purify functionality as viewhelper and service class to purify HTML code from unwanted HTML tags or HTML code containing XSS content.',
     'category' => 'fe',
     'author' => 'Sebastian Müller',
     'author_email' => 'sebastian.mueller@elementare-teilchen.de',
     'state' => 'stable',
-    'internal' => '',
-    'uploadfolder' => '0',
-    'createDirs' => '',
-    'clearCacheOnLoad' => 0,
-    'version' => '1.2.0',
-    'constraints' => array(
-        'depends' => array(
-            'typo3' => '10.4.0-11.5.99',
-        ),
-        'conflicts' => array(
-        ),
-        'suggests' => array(
-        ),
-    ),
-);
+    'version' => '2.0.0',
+    'constraints' => [
+        'depends' => [
+            'typo3' => '11.5.0-12.4.99'
+        ],
+        'conflicts' => [],
+        'suggests' => []
+    ],
+];
diff --git a/ext_localconf.php b/ext_localconf.php
index 29ae023..6b1e4dd 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -1,6 +1,6 @@
 <?php
 
-defined('TYPO3_MODE') || die('Access denied.');
+defined('TYPO3') || die('Access denied.');
 
 if (!\TYPO3\CMS\Core\Core\Environment::isComposerMode()) {
     require \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::extPath('html_purify') . '/Resources/Private/Php/Libraries/vendor/autoload.php';