diff --git a/Jellyfin.Api/Controllers/AttachmentsController.cs b/Jellyfin.Api/Controllers/AttachmentsController.cs
index 5d48a79b9b..f4c1a761fb 100644
--- a/Jellyfin.Api/Controllers/AttachmentsController.cs
+++ b/Jellyfin.Api/Controllers/AttachmentsController.cs
@@ -1,3 +1,5 @@
+#nullable enable
+
 using System;
 using System.Threading;
 using System.Threading.Tasks;