diff --git a/ChangeLog.n b/ChangeLog.n
index 354ee13d0994dbe22ea174e330ee0a190e2f3175..71fb5c0a30e4567f14792e4d9eab962b566f52b7 100644
--- a/ChangeLog.n
+++ b/ChangeLog.n
@@ -2,8 +2,12 @@
 *** LEAVE THIS AT THE TOP OF THE FILE ***
 don't forget to change the version in utils/packages.lisp if you do anything
 user visible.
-
 *******************************************************************************
+
+2009-07-15  Kevin Layer  <layer@gemini.franz.com>
+
+	* Makefile.macosx: ppc => i386; error on 64-bit Mac OS X
+
 2009-06-29  Andreas Fuchs  <afuchs@franz.com>
 
 	* aclpc/acl-frames.lisp: Fix types and ff call arguments in
diff --git a/Makefile.macosx b/Makefile.macosx
index 0ff46cd2d66ac58ad915d23e9c9ac16eb1484e97..501f150367fdceb5a273134d5f12533854f2b711 100644
--- a/Makefile.macosx
+++ b/Makefile.macosx
@@ -25,7 +25,8 @@ XLIB=-L/usr/X11R6/lib -lX11
 XINCLUDES=-I/usr/X11R6/include -I/usr/local/motif/include
 
 ifeq ($(SIXTYFOURBIT),yes)
-CFLAGS= -arch ppc64 -DAcl64Bit
+$(error CLIM does not work on 64-bit Mac OS X yet.)
+CFLAGS = -arch i386 -DAcl64Bit
 MAKE_SHARED = sh ../src/bin/make_shared.mac64
 else
 ifeq ($(MACHINE),x86)