--- Makefile.orig	2015-10-14 14:25:18.000000000 +0000
+++ Makefile	2019-01-03 07:21:17.000000000 +0000
@@ -2,7 +2,8 @@
 
 DEBUG=-g
 LDFLAGS=-liconv_hook -lmrss $(DEBUG)
-CFLAGS=-O3 -Wall -DVERSION=\"$(VERSION)\" $(DEBUG)
+CFLAGS=-O3 -Wall $(DEBUG)
+override CFLAGS+=-DVERSION=\"$(VERSION)\"
 
 OBJS=r2t.o