--- Makefile.in.orig	Wed Oct 20 23:02:06 1999
+++ Makefile.in	Wed Oct 20 23:02:19 1999
@@ -1,7 +1,7 @@
 DEFS=-DHAVE_CONFIG_H
-PREFIX=/usr/local
+PREFIX?=/usr/local
 
-CFLAGS=-O2 -g -Wall $(DEFS)
+CFLAGS+=-Wall $(DEFS)
 
 OBJS=chm.o