diff --git a/lib/classes/JsonApi/Routes/Courseware/UnitsCreate.php b/lib/classes/JsonApi/Routes/Courseware/UnitsCreate.php
index 5909f2aa473e9c2a7110ae860e4c80815c796756..e676507017da96fa0e103f7f70975a86beee71a5 100644
--- a/lib/classes/JsonApi/Routes/Courseware/UnitsCreate.php
+++ b/lib/classes/JsonApi/Routes/Courseware/UnitsCreate.php
@@ -114,7 +114,7 @@ class UnitsCreate extends JsonApiController
 
         $instance = new \Courseware\Instance($struct);
 
-        $instance->setRootLayout(self::arrayGet($json, 'data.attributes.settings.root-layout'));
+        $instance->setRootLayout(self::arrayGet($json, 'data.attributes.settings.root-layout') ?? 'default');
 
         $instance->getUnit()->store();