diff --git a/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php b/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
index bbcfda412e3c..725539a63d98 100644
--- a/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
+++ b/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
@@ -2274,7 +2274,7 @@ protected function processNonCacheableContentPartsAndSubstituteContentMarkers(ar
             // If the split had a comment-end after 32 characters it's probably a split-string
             if (substr($contentPart, 32, 3) === '-->') {
                 $nonCacheableKey = 'INT_SCRIPT.' . substr($contentPart, 0, 32);
-                if (is_array($nonCacheableData[$nonCacheableKey])) {
+                if (is_array($nonCacheableData[$nonCacheableKey] ?? false)) {
                     $label = 'Include ' . $nonCacheableData[$nonCacheableKey]['type'];
                     $timeTracker->push($label);
                     $nonCacheableContent = '';