Index: gdo/Makefile
===================================================================
--- gdo.orig/Makefile	2011-10-11 18:47:57.013045759 +0200
+++ gdo/Makefile	2011-10-11 18:56:41.173056205 +0200
@@ -26,8 +26,8 @@
 ifdef FT2_LIB
 FT2_FLAG = -DHAVE_FREETYPE
 endif
-CFLAGS = $(CINCLUDES) -fPIC -W -Wall -Wno-unused \
-	$(JPEG_FLAG) $(FT2_FLAG) $(SAFETY_FLAG)
+override CFLAGS += $(CINCLUDES) -fPIC -W -Wall -Wno-unused \
+		   $(JPEG_FLAG) $(FT2_FLAG) $(SAFETY_FLAG)
 
 OCAMLCFLAGS=-labels -unsafe
 OCAMLOPTFLAGS=-labels -inline 2
