diff --git a/src/macgui.h b/src/macgui.h
index 579ae2b7663..c09f1a8d173 100644
--- a/src/macgui.h
+++ b/src/macgui.h
@@ -81,11 +81,13 @@ typedef unsigned long Time;
 
 /* Whether to use ATSUI (Apple Type Services for Unicode Imaging) for
    text drawing.  */
+#if 0 /* Don't enable by default on the emacs-unicode-2 branch.  */
 #ifndef USE_ATSUI
 #ifdef MAC_OSX
 #define USE_ATSUI 1
 #endif
 #endif
+#endif
 
 /* Whether to use low-level Quartz 2D (aka Core Graphics) text drawing
    in preference to ATSUI for ASCII and Latin-1 characters.  */