--- ./doc/Makefile.orig	2014-05-19 15:47:03.978020008 +0800
+++ ./doc/Makefile	2014-05-19 15:47:12.697019517 +0800
@@ -52,6 +52,6 @@
 all:
 
 install:
-	install -C -m 444 dbow.1 $(PREFIX)/man/man1
+	install -C -m 444 dbow.1 $(DESTDIR)$(PREFIX)/man/man1
 
 clean:
