diff --git a/Makefile b/Makefile
index 01c2325..b5e9888 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-prefix=/usr/local
+prefix?=/usr/local
 sbindir=$(prefix)/sbin
 datadir=$(prefix)/share
 mandir=$(datadir)/man