diff --git a/LICENSE b/LICENSE
index 9f98c8d..111f57e 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,7 @@
 The MIT License (MIT)
 
-Copyright (c) 2023 Alon Swartz
+Copyright (c) 2023 Alon Swartz (Notesium, upstream project)
+Copyright (c) 2026 librenotes contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the
diff --git a/NOTICE b/NOTICE
index 125c0b0..0e30307 100644
--- a/NOTICE
+++ b/NOTICE
@@ -3,11 +3,36 @@ librenotes
 
 Cloud-native multi-tenant notes application.
 
-This project is a fork of Notesium (https://github.com/alonswartz/notesium),
-created and maintained by Alon Swartz, licensed under the MIT License.
+Fork origin
+-----------
+
+This project is a fork of Notesium, created and maintained by Alon Swartz.
+
+Upstream repository:  https://github.com/alonswartz/notesium
+Upstream license:     MIT
+Forked at commit:     aff9f460c2d864112db7f0935b4168b107289d91
+Fork date:            2026-04-28
 
 The original Notesium code is preserved under internal/notesium/ and remains
-under the MIT license. See LICENSE for the full license text.
+under the MIT license. See LICENSE for the full license text and the combined
+copyright notice.
 
 Modifications and additions made for librenotes are also released under the
 MIT License.
+
+Working with the upstream remote
+--------------------------------
+
+Contributors who want to follow upstream Notesium development or cherry-pick
+fixes from upstream can add the upstream remote:
+
+    git remote add upstream https://github.com/alonswartz/notesium.git
+    git fetch upstream
+
+To inspect upstream changes since the fork point:
+
+    git log aff9f460c2d864112db7f0935b4168b107289d91..upstream/master
+
+Note that the librenotes layout differs from upstream (sources moved into
+internal/notesium/), so direct merges will conflict. Cherry-picking
+individual upstream patches is the expected workflow.