--- ./GNUmakefile.orig	2021-11-10 19:35:46.973265640 +0000
+++ ./GNUmakefile	2021-11-10 19:34:58.803308861 +0000
@@ -7,11 +7,11 @@
 
 name=		mg
 
-prefix=		/usr/local
+prefix?=		/usr/local
 bindir=		$(prefix)/bin
 libdir=		$(prefix)/lib
 includedir=	$(prefix)/include
-mandir=		$(prefix)/man
+mandir=		$(prefix)/share/man
 
 PKG_CONFIG=	/usr/bin/pkg-config --silence-errors
 INSTALL=	/usr/bin/install