diff --git a/library/pydfhack/DF_API.cpp b/library/pydfhack/DF_API.cpp
index 0b5c46f9d..da47424c0 100644
--- a/library/pydfhack/DF_API.cpp
+++ b/library/pydfhack/DF_API.cpp
@@ -1,3 +1,27 @@
+/*
+www.sourceforge.net/projects/dfhack
+Copyright (c) 2009 Petr Mrázek (peterix), Kenneth Ferland (Impaler[WrG]), dorf, doomchild
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any
+damages arising from the use of this software.
+
+Permission is granted to anyone to use this software for any
+purpose, including commercial applications, and to alter it and
+redistribute it freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must
+not claim that you wrote the original software. If you use this
+software in a product, an acknowledgment in the product documentation
+would be appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and
+must not be misrepresented as being the original software.
+
+3. This notice may not be removed or altered from any source
+distribution.
+*/
+
 #ifndef __DFAPI__
 #define __DFAPI__