diff --git a/lib/Service/System/SystemInfoService.php b/lib/Service/System/SystemInfoService.php
index 7257080..65ad2a1 100644
--- a/lib/Service/System/SystemInfoService.php
+++ b/lib/Service/System/SystemInfoService.php
@@ -89,7 +89,7 @@ class SystemInfoService
         if ($this->moduleRegistry !== null) {
             foreach ($this->moduleRegistry->getModules() as $manifest) {
                 foreach ($manifest->permissions as $perm) {
-                    $key = $perm['key'] ?? '';
+                    $key = $perm['key'];
                     if ($key !== '') {
                         $moduleKeys[$key] = $manifest->id;
                     }