--- Makefile.orig	1993-08-12 14:09:31 UTC
+++ Makefile
@@ -1,7 +1,7 @@
 # @(#) Makefile 1.2 93/08/12 16:09:29
 
 FILES	= README Makefile chrootuid.c chrootuid.1
-CFLAGS	= -O 
+CFLAGS	?= -O 
 
 all:	chrootuid chrootuid.1