diff --git a/Include/pythread.h b/Include/pythread.h
index 752ab6d9676..c5048491e4c 100644
--- a/Include/pythread.h
+++ b/Include/pythread.h
@@ -1,5 +1,36 @@
-#ifndef _THREAD_H_included
-#define _THREAD_H_included
+#ifndef Py_PYTHREAD_H
+#define Py_PYTHREAD_H
+
+/***********************************************************
+Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
+The Netherlands.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI or Corporation for National Research Initiatives or
+CNRI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior
+permission.
+
+While CWI is the initial source for this software, a modified version
+is made available by the Corporation for National Research Initiatives
+(CNRI) at the Internet address ftp://ftp.python.org.
+
+STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
+CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
 
 #define NO_EXIT_PROG		/* don't define PyThread_exit_prog() */
 				/* (the result is no use of signals on SGI) */
@@ -53,4 +84,4 @@ DL_IMPORT(void *) PyThread_get_key_value Py_PROTO((int));
 }
 #endif
 
-#endif
+#endif /* !Py_PYTHREAD_H */