--- Makefile.orig	2014-01-07 14:46:08.000000000 +0800
+++ Makefile	2014-01-07 14:46:17.000000000 +0800
@@ -6,7 +6,7 @@ all:
 	$(CC) ${CFLAGS} bug5.c -o bug5 ${LDFLAGS}
 
 install:
-	install -m 555 bug5 ${PREFIX}/bin
+	install -m 555 bug5 $(DESTDIR)${PREFIX}/bin
 
 clean:
 	rm -f bug5