diff --git a/Classes/Hooks/TceMain.php b/Classes/Hooks/TceMain.php
index bfe96f3..29cb613 100644
--- a/Classes/Hooks/TceMain.php
+++ b/Classes/Hooks/TceMain.php
@@ -23,7 +23,7 @@ public function clearCacheCmd($params, &$parent): void
     {
         $backendUser = $this->getBackendUser();
         if ($backendUser->isAdmin() || $backendUser->getTSConfig()) {
-            $this->cacheManager->clearCache($params['cacheCmd']);
+            $this->cacheManager->clearCache($params['cacheCmd'] ?? null);
         }
     }