diff --git a/lib/models/Courseware/StructuralElement.php b/lib/models/Courseware/StructuralElement.php
index 3e405f3b2f01d10710ef3047395dd56dc55a7117..fabfd8465e6638751ae88ff7381767a0e6f2c340 100644
--- a/lib/models/Courseware/StructuralElement.php
+++ b/lib/models/Courseware/StructuralElement.php
@@ -374,7 +374,7 @@ class StructuralElement extends \SimpleORMap implements \PrivacyObject
         $unit = $this->findUnit();
         return $GLOBALS['perm']->have_perm('root', $user->id)
             || $GLOBALS['perm']->have_studip_perm(
-                $unit->config['editing_permission'],
+                $unit->config['editing_permission'] ?? 'tutor',
                 $this->range_id,
                 $user->id
             );