diff --git a/Classes/ErrorHandler.php b/Classes/ErrorHandler.php
index fd90a64..314ed5d 100644
--- a/Classes/ErrorHandler.php
+++ b/Classes/ErrorHandler.php
@@ -138,7 +138,7 @@ protected function getPageUid_403($fe_group)
     protected function getExtConf()
     {
         if (is_null($this->extConf)) {
-            $this->extConf = $GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['fox_handler'];
+            $this->extConf = $GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['fox_handler'] ?? [];
         }
 
         return $this->extConf;