Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -1,8 +1,7 @@
 PROG=		moo
-SRCS=		moo.c scan.c
+SRCS=		moo.y scan.l
 CPPFLAGS+=	-I${.CURDIR}
 COPTS+=		-Wall -W -Wno-unused -Wshadow -pedantic -std=c99
-CLEANFILES+=	moo.c y.tab.h scan.c lex.yy.c
 
 LOCALBASE?=/usr/local
 BINDIR=${LOCALBASE}/bin