--- Makefile.orig	2011-08-21 20:17:01.000000000 +0800
+++ Makefile	2014-02-21 09:40:52.782172201 +0800
@@ -15,7 +15,7 @@
 QUIET_SPARSE	= @true
 endif
 
-PREFIX ?= /usr/local
+PREFIX ?= $(DESTDIR)$(PREFIX)
 CFLAGS		?= -Os -fomit-frame-pointer
 CFLAGS		+= -std=c99 -Wall -pedantic -D_BSD_SOURCE
 LDFLAGS		?=
@@ -51,10 +51,10 @@
 	$(QUIET_CC) $(CFLAGS) -o $(BIN) $(call OBJS,$(SRCS)) $(LDFLAGS)
 
 install: all
-	install -d -o 0 -g 0 -m 755 $(PREFIX)/bin/
-	install -o 0 -g 0 -m 755 $(BIN) $(PREFIX)/bin/
-	install -d -o 0 -g 0 -m 755 $(PREFIX)/man/man1/
-	install -o 0 -g 0 -m 644 $(BIN).1 $(PREFIX)/man/man1/
+	install -d -m 755 $(DESTDIR)$(PREFIX)/bin/
+	$(BSD_INSTALL_PROGRAM) $(BIN) $(DESTDIR)$(PREFIX)/bin/
+	install -d -m 755 $(DESTDIR)$(PREFIX)/man/man1/
+	$(BSD_INSTALL_MAN) $(BIN).1 $(DESTDIR)$(PREFIX)/man/man1/
 
 clean:
 	-rm -Rf obj dep *.orig *.rej *~