diff --git a/Classes/Hooks/PageRendererPreProcess.php b/Classes/Hooks/PageRendererPreProcess.php
index 1379a9e..5dc4a0a 100644
--- a/Classes/Hooks/PageRendererPreProcess.php
+++ b/Classes/Hooks/PageRendererPreProcess.php
@@ -16,7 +16,7 @@ class PageRendererPreProcess
     public function __construct(AssetCollector $assetCollector = null)
     {
         $this->assetCollector = $assetCollector ?? GeneralUtility::makeInstance(AssetCollector::class);
-        $this->tsfe = $GLOBALS['TSFE'];
+        $this->tsfe = $GLOBALS['TSFE'] ?? null;
     }
 
     public function addLibrary(): void