diff --git a/Classes/Configuration/ConfigurationContainer.php b/Classes/Configuration/ConfigurationContainer.php
index eab76e0..aaf0ebb 100644
--- a/Classes/Configuration/ConfigurationContainer.php
+++ b/Classes/Configuration/ConfigurationContainer.php
@@ -21,7 +21,7 @@ namespace Codappix\SearchCore\Configuration;
  */
 
 use TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface;
-use TYPO3\CMS\Extbase\Utility\ArrayUtility;
+use TYPO3\CMS\Core\Utility\ArrayUtility;
 
 /**
  * Container of all configurations for extension.
diff --git a/Classes/Domain/Model/SearchRequest.php b/Classes/Domain/Model/SearchRequest.php
index 3c88871..a375d24 100644
--- a/Classes/Domain/Model/SearchRequest.php
+++ b/Classes/Domain/Model/SearchRequest.php
@@ -93,7 +93,9 @@ class SearchRequest implements SearchRequestInterface
     public function setFilter(array $filter)
     {
         $filter = \TYPO3\CMS\Core\Utility\ArrayUtility::removeArrayEntryByValue($filter, '');
-        $this->filter = \TYPO3\CMS\Extbase\Utility\ArrayUtility::removeEmptyElementsRecursively($filter);
+        $this->filter = \TYPO3\CMS\Core\Utility\ArrayUtility::filterRecursive($filter, function ($value) {
+            return !empty($value);
+        });
     }
 
     public function hasFilter() : bool
diff --git a/Classes/Domain/Search/QueryFactory.php b/Classes/Domain/Search/QueryFactory.php
index 98e3324..a2f6c43 100644
--- a/Classes/Domain/Search/QueryFactory.php
+++ b/Classes/Domain/Search/QueryFactory.php
@@ -25,7 +25,7 @@ use Codappix\SearchCore\Configuration\ConfigurationUtility;
 use Codappix\SearchCore\Configuration\InvalidArgumentException;
 use Codappix\SearchCore\Connection\SearchRequestInterface;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
-use TYPO3\CMS\Extbase\Utility\ArrayUtility;
+use TYPO3\CMS\Core\Utility\ArrayUtility;
 
 class QueryFactory
 {
diff --git a/ext_localconf.php b/ext_localconf.php
index 658d683..810b3eb 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -5,7 +5,7 @@ call_user_func(
         // TODO: Add hook for Extbase -> to handle records modified through
         // Frontend and backend modules not using datahandler
 
-        $GLOBALS['TYPO3_CONF_VARS'] = TYPO3\CMS\Extbase\Utility\ArrayUtility::arrayMergeRecursiveOverrule(
+        \TYPO3\CMS\Core\Utility\ArrayUtility::mergeRecursiveWithOverrule(
             $GLOBALS['TYPO3_CONF_VARS'],
             [
                 'SC_OPTIONS' => [
@@ -43,7 +43,8 @@ call_user_func(
         \Codappix\SearchCore\Compatibility\ImplementationRegistrationService::registerImplementations();
 
         // API does make use of object manager, therefore use GLOBALS
-        $extensionConfiguration = unserialize($GLOBALS['TYPO3_CONF_VARS']['EXT']['extConf'][$extensionKey]);
+        $extensionConfiguration = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Configuration\ExtensionConfiguration::class)->get($extensionKey);
+
         if ($extensionConfiguration === false
             || !isset($extensionConfiguration['disable.']['elasticsearch'])
             || $extensionConfiguration['disable.']['elasticsearch'] !== '1'