diff --git a/radicale/app/proppatch.py b/radicale/app/proppatch.py
index c15fddfe..1d2701a0 100644
--- a/radicale/app/proppatch.py
+++ b/radicale/app/proppatch.py
@@ -2,7 +2,9 @@
 # Copyright © 2008 Nicolas Kandel
 # Copyright © 2008 Pascal Halter
 # Copyright © 2008-2017 Guillaume Ayoub
-# Copyright © 2017-2018 Unrud <unrud@outlook.com>
+# Copyright © 2017-2020 Unrud <unrud@outlook.com>
+# Copyright © 2020-2020 Tuna Celik <tuna@jakpark.com>
+# Copyright © 2025-2025 Peter Bieringer <pb@bieringer.de>
 #
 # This library is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by