--- a/Makefile	2006-07-07 00:54:10.000000000 +0200
+++ b/Makefile	2018-10-27 02:19:51.000000000 +0200
@@ -1,4 +1,4 @@
-CFLAGS = -O2 -Wall -Wstrict-prototypes
+CFLAGS += -Wall -Wstrict-prototypes
 
 VERSION=0.1
 DATE="July 6, 2006"
@@ -12,9 +12,12 @@
 	M=`echo $(DATE)`; sed <$< >$@ "s/@TODAY@/$$M/;s/@VERSION@/pnputils-$(VERSION)/;"
 
 install: all
-	install -m 755 lspnp setpnp /sbin
-	install -m 644 lspnp.8 setpnp.8 /usr/share/man/man8
-	install -m 644 pnp.ids /usr/share/misc
+	install -m 755 -d $(DESTDIR)/usr/sbin
+	install -m 755 lspnp setpnp $(DESTDIR)/usr/sbin
+	install -m 755 -d $(DESTDIR)/usr/share/man/man8
+	install -m 644 lspnp.8 setpnp.8 $(DESTDIR)/usr/share/man/man8
+	install -m 755 -d $(DESTDIR)/usr/share/misc
+	install -m 644 pnp.ids $(DESTDIR)/usr/share/misc
 
 REL=pnputils-$(VERSION)
 DISTTMP=/tmp/pnputils-dist