diff --git GNUmakefile GNUmakefile
index 3f3193d..43b1b55 100644
--- GNUmakefile
+++ GNUmakefile
@@ -4,10 +4,10 @@
 # in /opt/diet, where they are in the default search path for my diet libc
 # work but don't conflict with anything there.  YMMV.
 
-prefix=/opt/diet
+prefix=STAGEDIR${PREFIX}
 LIBDIR=${prefix}/lib
-INCLUDEDIR=${prefix}/include
-MAN3DIR=${prefix}/man/man3
+INCLUDEDIR=${prefix}/include/libowfat
+MAN3DIR=STAGEDIR${MANPREFIX}/man/man3
 
 LIBS=byte.a fmt.a scan.a str.a uint.a open.a stralloc.a unix.a socket.a \
 buffer.a mmap.a taia.a tai.a dns.a case.a mult.a array.a io.a \
@@ -18,26 +18,14 @@ all: headers ent $(LIBS) libowfat.a libsocket t
 pic pie:
 	$(MAKE) CC="gcc -fPIC" LDFLAGS="-fpie"
 
-CROSS=
-#CROSS=i686-mingw-
-CC?=gcc
-CCC=$(CROSS)$(CC)
+CCC=${CC}
 WERROR=
 WARN=-W -Wall -Wextra $(WERROR)
 
-# Use the second version if you are building for a binary that is only
-# supposed to run on this machine. It tells gcc to use CPU instructions
-# that are specific to the CPU the code is compiled on.
-NATIVE=
-#NATIVE=-march=native -mtune=native
-
-OPT_REG=-O2
-OPT_PLUS=-O3 $(NATIVE)
-
 DEFINE=-D_REENTRANT
 
-CFLAGS=-pipe $(WARN) $(DEFINE) $(OPT_REG)
-CFLAGS_OPT=-pipe $(WARN) $(DEFINE) $(OPT_PLUS)
+CFLAGS+=-pipe $(WARN) $(DEFINE)
+CFLAGS_OPT=$(CFLAGS)
 
 #CFLAGS=-pipe -Os -march=pentiumpro -mcpu=pentiumpro -fomit-frame-pointer -fschedule-insns2 -Wall
 
@@ -217,16 +205,16 @@ libowfat/%.h: %.h
 	ln -f $< $@
 
 install-inc:
-	install -d $(DESTDIR)$(INCLUDEDIR)/libowfat
-	install -m 644 $(INCLUDES) $(DESTDIR)$(INCLUDEDIR)/libowfat
+	${INSTALL} -d $(INCLUDEDIR)
+	${BSD_INSTALL_DATA} -m 644 $(INCLUDES) $(INCLUDEDIR)
 
 install-lib: libowfat.a
-	install -d $(DESTDIR)$(LIBDIR)
-	install -m 644 libowfat.a $(DESTDIR)$(LIBDIR)
+	${INSTALL} -d $(LIBDIR)
+	${BSD_INSTALL_DATA} -m 644 libowfat.a $(LIBDIR)
 
 install-man:
-	install -d $(DESTDIR)$(MAN3DIR)
-	install -m 644 $(wildcard */*.3) $(DESTDIR)$(MAN3DIR)
+	${INSTALL} -d $(MAN3DIR)
+	${BSD_INSTALL_MAN} -m 644 $(wildcard */*.3) $(MAN3DIR)
 
 install: headers install-inc install-man install-lib