diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index afeab8df311c..d10e4f3190e6 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2008-01-26  David Edelsohn  <edelsohn@gnu.org>
+
+	PR target/34794
+	* config/os/aix/os_defines.h: Define __COMPATMATH__.
+
 2008-01-24  David Edelsohn  <edelsohn@gnu.org>
 
 	* configure: Regenerate.
diff --git a/libstdc++-v3/config/os/aix/os_defines.h b/libstdc++-v3/config/os/aix/os_defines.h
index 8f1f8138ab65..2aa9f7fc2cb3 100644
--- a/libstdc++-v3/config/os/aix/os_defines.h
+++ b/libstdc++-v3/config/os/aix/os_defines.h
@@ -1,6 +1,6 @@
 // Specific definitions for AIX  -*- C++ -*-
 
-// Copyright (C) 2000, 2002, 2005 Free Software Foundation, Inc.
+// Copyright (C) 2000, 2002, 2005, 2008 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -48,4 +48,9 @@
 #define _ALL_SOURCE
 #endif
 
+// C99 math
+#ifndef __COMPATMATH__
+#define __COMPATMATH__
+#endif
+
 #endif