--- Makefile.x	2010-07-19 21:05:53.000000000 +0200
+++ Makefile	2010-07-19 21:06:00.000000000 +0200
@@ -1,4 +1,4 @@
-prefix=/usr/local
+prefix?=/usr/local
 sbindir=$(prefix)/sbin
 datadir=$(prefix)/share
 mandir=$(datadir)/man