diff --git a/ext_localconf.php b/ext_localconf.php
index fe7a5367d..34cd30d3e 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -82,9 +82,8 @@
     $GLOBALS['TYPO3_CONF_VARS']['FE']['eID_include']['tx_dlf_pageview_proxy'] = \Kitodo\Dlf\Eid\PageViewProxy::class . '::main';
 }
 // Use Caching Framework for Solr queries
-if (!isset($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr']) || !is_array($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr'])) {
-    $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr'] = [];
-}
+$GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr'] ??= [];
+
 if (!isset($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr']['backend'])) {
     $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr']['backend'] = 'TYPO3\\CMS\\Core\\Cache\\Backend\\FileBackend';
 }
@@ -92,9 +91,8 @@
     $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_solr']['options']['defaultLifeTime'] = 86400; // 86400 seconds = 1 day
 }
 // Use Caching Framework for XML file caching
-if (!isset($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc']) || !is_array($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc'])) {
-    $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc'] = [];
-}
+$GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc'] ??= [];
+
 if (!isset($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc']['backend'])) {
     $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['tx_dlf_doc']['backend'] = 'TYPO3\\CMS\\Core\\Cache\\Backend\\FileBackend';
 }