diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d2b1cc423bdcc76140d7f29600f6eb3af8450334..76d0463ea81645427fb5389de3c6bee415aa9eb8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-10-26  Geoffrey Keating  <geoffk@apple.com>
+
+	PR 18149
+	* config/i386/darwin.h (ASM_SPEC): Undef it before defining.
+
 2004-10-25  Geoffrey Keating  <geoffk@apple.com>
 
 	* config/darwin.h (LINK_SPEC): Default weak_reference_mismatches
diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h
index 0b3db813e6c4a712ab4445d93f91a39fdd100dc0..c7b583d14bf7f40df10ac904033289bc87665605 100644
--- a/gcc/config/i386/darwin.h
+++ b/gcc/config/i386/darwin.h
@@ -44,6 +44,7 @@ Boston, MA 02111-1307, USA.  */
   %{gfull: -g -fno-eliminate-unused-debug-symbols %<gfull }\
   %{g: %{!gfull: -feliminate-unused-debug-symbols %<gfull }}"
 
+#undef ASM_SPEC
 #define ASM_SPEC "-arch i686 \
   -force_cpusubtype_ALL \
   %{Zforce_cpusubtype_ALL:-force_cpusubtype_ALL} \