diff --git a/src/win32/i_system.cpp b/src/win32/i_system.cpp
index 52f054dc2..2dc6c4d3d 100644
--- a/src/win32/i_system.cpp
+++ b/src/win32/i_system.cpp
@@ -4,6 +4,8 @@
 **
 **---------------------------------------------------------------------------
 ** Copyright 1998-2009 Randy Heit
+** Copyright (C) 2007-2012 Skulltag Development Team
+** Copyright (C) 2007-2016 Zandronum Development Team
 ** All rights reserved.
 **
 ** Redistribution and use in source and binary forms, with or without
@@ -17,6 +19,15 @@
 **    documentation and/or other materials provided with the distribution.
 ** 3. The name of the author may not be used to endorse or promote products
 **    derived from this software without specific prior written permission.
+** 4. Redistributions in any form must be accompanied by information on how to
+**    obtain complete source code for the software and any accompanying software
+**    that uses the software. The source code must either be included in the
+**    distribution or be available for no more than the cost of distribution plus
+**    a nominal fee, and must be freely redistributable under reasonable
+**    conditions. For an executable file, complete source code means the source
+**    code for all modules it contains. It does not include source code for
+**    modules or files that typically accompany the major components of the
+**    operating system on which the executable file runs.
 **
 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 ** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES