Index: contrib/byacc/main.c
===================================================================
--- contrib/byacc/main.c
+++ contrib/byacc/main.c
@@ -242,7 +242,7 @@
 #if defined(YYBTYACC)
 	backtrack = 1;
 #else
-	unsupported_flag_warning("-B", "reconfigure with --enable-btyacc");
+	unsupported_flag_warning("-B", "use btyacc(1)");
 #endif
 	break;
 
@@ -266,7 +266,7 @@
 #if defined(YYBTYACC)
 	locations = 1;
 #else
-	unsupported_flag_warning("-L", "reconfigure with --enable-btyacc");
+	unsupported_flag_warning("-L", "use btyacc(1)");
 #endif
 	break;
 
Index: usr.bin/Makefile
===================================================================
--- usr.bin/Makefile
+++ usr.bin/Makefile
@@ -252,6 +252,7 @@
 SUBDIR.${MK_TFTP}+=	tftp
 SUBDIR.${MK_TOOLCHAIN}+=	addr2line
 SUBDIR.${MK_TOOLCHAIN}+=	ar
+SUBDIR.${MK_TOOLCHAIN}+=	btyacc
 SUBDIR.${MK_TOOLCHAIN}+=	c89
 SUBDIR.${MK_TOOLCHAIN}+=	c99
 SUBDIR.${MK_TOOLCHAIN}+=	ctags
Index: usr.bin/btyacc/Makefile
===================================================================
--- /dev/null
+++ usr.bin/btyacc/Makefile
@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+.include <src.opts.mk>
+
+PROG=	btyacc
+
+.include "${SRCTOP}/usr.bin/yacc/Makefile.inc"
+
+SRCS+=	btyaccpar.c
+
+CFLAGS+=	-DYYBTYACC=1
+
+${PROG}.1: yacc.1
+	${CP} ${.ALLSRC} ${.TARGET}
+
+.include <bsd.prog.mk>
Index: usr.bin/yacc/Makefile
===================================================================
--- usr.bin/yacc/Makefile
+++ usr.bin/yacc/Makefile
@@ -3,20 +3,11 @@
 
 .include <src.opts.mk>
 
-BYACC_SRC=	${SRCTOP}/contrib/byacc
-.PATH: ${BYACC_SRC}
-
 PROG=	yacc
-SRCS=	closure.c error.c graph.c lalr.c lr0.c main.c mkpar.c mstring.c output.c \
-	reader.c yaccpar.c symtab.c verbose.c warshall.c
 
-CFLAGS+=	-DHAVE_FCNTL_H=1 \
-		-DHAVE_MKSTEMP=1 \
-		-DMAXTABLE=INT_MAX \
-		-DMIXEDCASE_FILENAMES=1
+.include "Makefile.inc"
 
-YYPATCH!=	cat ${BYACC_SRC}/VERSION
-CFLAGS+=	-DYYPATCH=${YYPATCH}
+SRCS+=	yaccpar.c
 
 LINKS=	${BINDIR}/yacc ${BINDIR}/byacc
 MLINKS=	yacc.1 byacc.1
Index: usr.bin/yacc/Makefile.inc
===================================================================
--- usr.bin/yacc/Makefile.inc
+++ usr.bin/yacc/Makefile.inc
@@ -1,14 +1,10 @@
-#	@(#)Makefile	5.3 (Berkeley) 5/12/90
 # $FreeBSD$
 
-.include <src.opts.mk>
-
 BYACC_SRC=	${SRCTOP}/contrib/byacc
 .PATH: ${BYACC_SRC}
 
-PROG=	yacc
 SRCS=	closure.c error.c graph.c lalr.c lr0.c main.c mkpar.c mstring.c output.c \
-	reader.c yaccpar.c symtab.c verbose.c warshall.c
+	reader.c symtab.c verbose.c warshall.c
 
 CFLAGS+=	-DHAVE_FCNTL_H=1 \
 		-DHAVE_MKSTEMP=1 \
@@ -17,11 +13,3 @@
 
 YYPATCH!=	cat ${BYACC_SRC}/VERSION
 CFLAGS+=	-DYYPATCH=${YYPATCH}
-
-LINKS=	${BINDIR}/yacc ${BINDIR}/byacc
-MLINKS=	yacc.1 byacc.1
-
-HAS_TESTS=
-SUBDIR.${MK_TESTS}+= tests
-
-.include <bsd.prog.mk>