diff --git a/share/mk/Makefile b/share/mk/Makefile
index e2239e44e431..1ae420145fe0 100644
--- a/share/mk/Makefile
+++ b/share/mk/Makefile
@@ -1,8 +1,8 @@
-#	$NetBSD: Makefile,v 1.11 1995/04/26 22:30:57 jtc Exp $
+#	$NetBSD: Makefile,v 1.12 1995/10/22 00:45:53 christos Exp $
 #	@(#)Makefile	5.3 (Berkeley) 6/22/90
 
 FILES=	bsd.README bsd.doc.mk bsd.dep.mk bsd.lib.mk bsd.man.mk bsd.nls.mk \
-	bsd.obj.mk bsd.own.mk bsd.prog.mk bsd.subdir.mk sys.mk
+	bsd.obj.mk bsd.own.mk bsd.prog.mk bsd.subdir.mk bsd.sys.mk sys.mk
 NOOBJ=	noobj
 
 install:
diff --git a/share/mk/bsd.README b/share/mk/bsd.README
index b3f2e59b999e..b9c153a6dac8 100644
--- a/share/mk/bsd.README
+++ b/share/mk/bsd.README
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.README,v 1.12 1995/09/24 23:49:06 christos Exp $
+#	$NetBSD: bsd.README,v 1.13 1995/10/22 00:45:54 christos Exp $
 #	@(#)bsd.README	5.1 (Berkeley) 5/11/90
 
 This is the README file for the new make "include" files for the BSD
@@ -274,6 +274,16 @@ SUBDIRS.
 
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 
+The include file <bsd.sys.mk> is used by <bsd.prog.mk> and
+<bsd.lib.mk>.  It contains a set of rules for lex and yacc that
+can be used when multiple lex and yacc files are present in the
+same directory, and their respective targets are made in parallel.
+Since it renames the yacc output include files these rules are not
+used by default. They can be enabled by setting the PARALLEL variable
+in the Makefile.
+
+=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+
 The include file <bsd.lib.mk> has support for building libraries.  It has
 the same seven targets as <bsd.prog.mk>: all, clean, cleandir, depend,
 install, lint, and tags.  It has a limited number of suffixes, consistent
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index d40f1b9b053a..4b459428469d 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.lib.mk,v 1.65 1995/09/30 12:21:33 pk Exp $
+#	$NetBSD: bsd.lib.mk,v 1.66 1995/10/22 00:45:56 christos Exp $
 #	@(#)bsd.lib.mk	5.26 (Berkeley) 5/2/91
 
 .if exists(${.CURDIR}/../Makefile.inc)
@@ -223,3 +223,4 @@ realinstall: beforeinstall
 .include <bsd.obj.mk>
 .include <bsd.dep.mk>
 .include <bsd.subdir.mk>
+.include <bsd.sys.mk>
diff --git a/share/mk/bsd.prog.mk b/share/mk/bsd.prog.mk
index 256885150742..ad668b041f81 100644
--- a/share/mk/bsd.prog.mk
+++ b/share/mk/bsd.prog.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.prog.mk,v 1.53 1995/06/25 22:29:02 cgd Exp $
+#	$NetBSD: bsd.prog.mk,v 1.54 1995/10/22 00:45:57 christos Exp $
 #	@(#)bsd.prog.mk	5.26 (Berkeley) 6/25/91
 
 .if exists(${.CURDIR}/../Makefile.inc)
@@ -148,3 +148,4 @@ lint: ${LOBJS}
 .include <bsd.obj.mk>
 .include <bsd.dep.mk>
 .include <bsd.subdir.mk>
+.include <bsd.sys.mk>
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
new file mode 100644
index 000000000000..0117215cb4d2
--- /dev/null
+++ b/share/mk/bsd.sys.mk
@@ -0,0 +1,30 @@
+# $NetBSD: bsd.sys.mk,v 1.1 1995/10/22 00:45:59 christos Exp $
+#
+# Parallel make rule overrides
+
+.if defined(PARALLEL)
+# Lex
+.l:
+	${LEX.l} -o${.TARGET:R}.yy.c ${.IMPSRC}
+	${LINK.c} -o ${.TARGET} ${.TARGET:R}.yy.c ${LDLIBS} -ll
+	rm -f ${.TARGET:R}.yy.c
+.l.c:
+	${LEX.l} -o${.TARGET} ${.IMPSRC}
+.l.o:
+	${LEX.l} -o${.TARGET:R}.yy.c ${.IMPSRC}
+	${COMPILE.c} -o ${.TARGET} ${.TARGET:R}.yy.c 
+	rm -f ${.TARGET:R}.yy.c
+
+# Yacc
+.y:
+	${YACC.y} -b ${.TARGET:R} ${.IMPSRC}
+	${LINK.c} -o ${.TARGET} ${.TARGET:R}.tab.c ${LDLIBS}
+	rm -f ${.TARGET:R}.tab.c
+.y.c:
+	${YACC.y} -b ${.TARGET:R} ${.IMPSRC}
+	mv ${.TARGET:R}.tab.c ${.TARGET}
+.y.o:
+	${YACC.y} -b ${.TARGET:R} ${.IMPSRC}
+	${COMPILE.c} -o ${.TARGET} ${.TARGET:R}.tab.c
+	rm -f ${.TARGET:R}.tab.c
+.endif