diff --git a/idm.py b/idm.py
index 23de402..bc30c5f 100644
--- a/idm.py
+++ b/idm.py
@@ -1,3 +1,10 @@
+# Based upon the fantastic Beacon eddy current scanner support
+#
+# Copyright (C) 2020-2023 Matt Baker <baker.matt.j@gmail.com>
+# Copyright (C) 2020-2023 Lasse Dalegaard <dalegaard@gmail.com>
+# Copyright (C) 2023 Beacon <beacon3d.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
 import threading
 import logging
 import chelper