diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 25dd9c1e2b9..4728a86d927 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-11-02  Andreas Schwab  <schwab@suse.de>
+
+	* config/ia64/fde-glibc.c (_GNU_SOURCE): Define to 1 instead of
+	empty to avoid conflict with the definition from configure.
+
 2003-11-02  Roger Sayle  <roger@eyesopen.com>
 
 	PR optimization/10817
diff --git a/gcc/config/ia64/fde-glibc.c b/gcc/config/ia64/fde-glibc.c
index 8c9b55a1b1e..15e19270f03 100644
--- a/gcc/config/ia64/fde-glibc.c
+++ b/gcc/config/ia64/fde-glibc.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+/* Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
    Contributed by Richard Henderson <rth@cygnus.com>.
 
    This file is part of GCC.
@@ -29,7 +29,7 @@
    to avoid register/deregister calls at DSO load/unload.  */
 
 #ifndef _GNU_SOURCE
-#define _GNU_SOURCE
+#define _GNU_SOURCE 1
 #endif
 #include "config.h"
 #include <stddef.h>