update file headers
diff --git a/serial/rs485.py b/serial/rs485.py
index 1a2d4d4..2939350 100644
--- a/serial/rs485.py
+++ b/serial/rs485.py
@@ -2,6 +2,7 @@
 
 # RS485 support
 #
+# This file is part of pySerial. https://github.com/pyserial/pyserial
 # (C) 2015 Chris Liechti <cliechti@gmx.net>
 #
 # SPDX-License-Identifier:    BSD-3-Clause