diff --git a/typo3/sysext/extbase/Classes/Utility/LocalizationUtility.php b/typo3/sysext/extbase/Classes/Utility/LocalizationUtility.php
index 8ef85baf5d51..a138d0444c36 100644
--- a/typo3/sysext/extbase/Classes/Utility/LocalizationUtility.php
+++ b/typo3/sysext/extbase/Classes/Utility/LocalizationUtility.php
@@ -196,7 +196,9 @@ protected static function getLanguageKeys(): array
             $siteLanguage = self::getCurrentSiteLanguage();
 
             // Get values from site language
-            $languageKeys['languageKey'] = $siteLanguage->getTypo3Language();
+            if ($siteLanguage !== null) {
+                $languageKeys['languageKey'] = $siteLanguage->getTypo3Language();
+            }
 
             $locales = GeneralUtility::makeInstance(Locales::class);
             if (in_array($languageKeys['languageKey'], $locales->getLocales())) {