--- Makefile.orig	1994-11-25 07:09:25.000000000 -0500
+++ Makefile	2014-03-29 11:43:43.000000000 -0400
@@ -3,10 +3,10 @@
 #
 
 # C compiler
-CC=gcc
+CC?=gcc
 
 # C compilation flags
-CFLAGS= -O -I../dbz
+CFLAGS+= -I../dbz
 
 # Loader flags
 LDFLAGS=
