diff -ruN ./sys/unix/Makefile.doc ../nethack-3.2.2/sys/unix/Makefile.doc
--- ./sys/unix/Makefile.doc	Wed Dec 11 05:20:08 1996
+++ ../nethack-3.2.2/sys/unix/Makefile.doc	Sun Mar 21 17:25:02 1999
@@ -31,7 +31,7 @@
 
 
 GAME	= nethack
-MANDIR	= /usr/man/man6
+MANDIR	= ${PREFIX}/man/man6
 MANEXT	= 6
 
 # manual installation for most BSD-style systems
