diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index dae90cd..d52134e 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -54,7 +54,6 @@ INCLUDES =						\
 	-DGTK_PRINT_BACKEND_ENABLE_UNSUPPORTED		\
 	$(GTK_DEBUG_FLAGS)				\
 	$(GTK_DEP_CFLAGS)				\
-	$(gtk_clipboard_dnd_c_sources_CFLAGS)		\
 	$(INCLUDED_IMMODULE_DEFINE)
 
 gtarget=$(gdktarget)
@@ -692,9 +691,9 @@ gtk_private_h_sources += gtkwin32embed.h gtkwin32embedwidget.h
 gtk_c_sources += $(gtk_use_win32_c_sources)
 else
 if USE_QUARTZ
+libgtk_quartz_3_0_la_CFLAGS = "-xobjective-c"
 gtk_private_h_sources += gtksearchenginequartz.h
 gtk_c_sources += $(gtk_use_quartz_c_sources)
-gtk_use_quartz_c_sources_CFLAGS = "-xobjective-c"
 else
 gtk_c_sources += $(gtk_use_stub_c_sources)
 endif
@@ -704,10 +703,8 @@ endif
 if USE_QUARTZ
 gtk_clipboard_dnd_c_sources = gtkclipboard-quartz.c gtkdnd-quartz.c gtkquartz.c
 gtk_clipboard_dnd_h_sources = gtkquartz.h
-gtk_clipboard_dnd_c_sources_CFLAGS = "-xobjective-c"
 else
 gtk_clipboard_dnd_c_sources = gtkclipboard.c gtkdnd.c
-gtk_clipboard_dnd_c_sources_CFLAGS =
 endif
 EXTRA_DIST += gtkquartz.h
 
