diff --git a/emulators/rtc/Makefile b/emulators/rtc/Makefile
index b20a7acfd7cb..ec92a8215c7a 100644
--- a/emulators/rtc/Makefile
+++ b/emulators/rtc/Makefile
@@ -6,7 +6,7 @@
 #
 
 PORTNAME=	rtc
-PORTVERSION=	2000.09.11
+PORTVERSION=	2000.09.22
 CATEGORIES=	emulators linux
 MASTER_SITES=	# none
 DISTFILES=	# none
@@ -25,13 +25,15 @@ STARTUP=	rtc.sh
 MAKE_ARGS=	KMODDIR="${KMODDIR}" CDEV_MAJOR="${CDEV_MAJOR}"
 PLIST_SUB=	DEVDIR="${DEVDIR}" CDEV_MAJOR="${CDEV_MAJOR}" RTC_H_DIR="${RTC_H_DIR}"
 
+SRC_BASE?=	/usr/src
+
 .include <bsd.port.pre.mk>
 
 .if ${OSVERSION} < 400013
 BROKEN=         "Systems prior to 400013 is out of support"
 .endif
 
-.if !exists(/sys/Makefile)
+.if !exists(${SRC_BASE}/sys/Makefile)
 BROKEN=         "Kernel source files required"
 .endif
 
@@ -45,10 +47,15 @@ do-extract:
 	@cd ${FILESDIR} && ${CP} Makefile *.[ch] ${WRKSRC}/
 
 post-patch:
-.if !exists(/sys/compat/linux/linux_ioctl.h)
+.if !exists(${SRC_BASE}/sys/compat/linux/linux_ioctl.h)
 	${PERL} -i -pe 's,compat(/linux/linux_ioctl\.h),i386$$1,' \
 		${WRKSRC}/rtc_linux.c
 .endif
+	@if ! grep -w dev2unit ${SRC_BASE}/sys/kern/kern_conf.c >/dev/null; \
+	then \
+		${ECHO} "dev2unit() not found in sys/kern/kern_conf.c.  Using lminor() instead."; \
+		${PERL} -i -pe 's,dev2unit,lminor,' ${WRKSRC}/rtc.c; \
+	fi
 
 pre-install:
 	${MKDIR} ${KMODDIR}
diff --git a/emulators/rtc/files/rtc.c b/emulators/rtc/files/rtc.c
index 95681ce5bdc0..ff6899e3251b 100644
--- a/emulators/rtc/files/rtc.c
+++ b/emulators/rtc/files/rtc.c
@@ -115,7 +115,7 @@ rtc_attach(dev_t dev)
 	struct rtc_softc *sc;
 	int unit;
 
-	unit = lminor(dev);
+	unit = dev2unit(dev);
 	DLog(Lenter, "%d %p", unit, dev);
 	if (dev->si_drv1) {
 		DLog(Lexit, "old %p, %p", dev, dev->si_drv1);
diff --git a/emulators/rtc/files/rtc.sh b/emulators/rtc/files/rtc.sh
index 5fa3843be1f4..8751f46c710d 100644
--- a/emulators/rtc/files/rtc.sh
+++ b/emulators/rtc/files/rtc.sh
@@ -1,12 +1,13 @@
 #!/bin/sh
 
-kmod=@@PREFIX@@/modules/rtc.ko
+kmoddir=@@PREFIX@@/modules
+kmod=rtc.ko
 
 case "$1" in
 start)
-	if [ -x $kmod ]; then
+	if [ -x $kmoddir/$kmod ]; then
 	    echo -n ' rtc'
-	    kldload $kmod
+	    kldload $kmoddir/$kmod
 	fi
 	;;
 stop)