diff --git a/Makefile b/Makefile
index c6d63a2..bc985a1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,11 @@
-PREFIX=/usr/local
+prefix=/usr/local
+sbindir=$(prefix)/sbin
+datadir=$(prefix)/share
+mandir=$(datadir)/man
 
-INSTALL=/usr/bin/install
+DESTDIR=
+
+INSTALL=install
 INSTALL_FLAGS=
 
 MKDIR=mkdir
@@ -13,16 +18,16 @@ all:
 	@(cd src; make all)
 
 install: all
-	$(MKDIR) $(MKDIR_FLAGS) $(PREFIX)/sbin
-	$(INSTALL) $(INSTALL_FLAGS) bin/iodine $(PREFIX)/sbin/iodine
-	$(INSTALL) $(INSTALL_FLAGS) bin/iodined $(PREFIX)/sbin/iodined
-	$(MKDIR) $(MKDIR_FLAGS) $(PREFIX)/man/man8
-	$(INSTALL) $(INSTALL_FLAGS) man/iodine.8 $(PREFIX)/man/man8/iodine.8
+	$(MKDIR) $(MKDIR_FLAGS) $(DESTDIR)$(sbindir)
+	$(INSTALL) $(INSTALL_FLAGS) bin/iodine $(DESTDIR)$(prefix)/iodine
+	$(INSTALL) $(INSTALL_FLAGS) bin/iodined $(DESTDIR)$(prefix)/iodined
+	$(MKDIR) $(MKDIR_FLAGS) $(DESTDIR)$(mandir)/man8
+	$(INSTALL) $(INSTALL_FLAGS) man/iodine.8 $(DESTDIR)$(mandir)/man8/iodine.8
 
 uninstall:
-	$(RM) $(RM_FLAGS) $(PREFIX)/sbin/iodine
-	$(RM) $(RM_FLAGS) $(PREFIX)/sbin/iodined
-	$(RM) $(RM_FLAGS) $(PREFIX)/man/man8/iodine.8
+	$(RM) $(RM_FLAGS) $(sbindir)/iodine
+	$(RM) $(RM_FLAGS) $(sbindir)/iodined
+	$(RM) $(RM_FLAGS) $(mandir)/man8/iodine.8
 	
 test: all
 	@(cd tests; make all)