--- makefile.orig	2009-06-23 11:49:24.000000000 +0400
+++ makefile	2009-06-23 11:50:10.000000000 +0400
@@ -1,10 +1,10 @@
 UNAME_S:=$(shell uname -s)
 
 # defaults
-CC = gcc
+CC ?= gcc
 OPTIONS=-g -Wall
-LDLIBS=-lc -lm
-CFLAGS=
+LDLIBS+=-lc -lm
+CFLAGS?=
 
 # FreeBSD
 ifeq ("FreeBSD", "$(UNAME_S)")
