diff --git a/release/tools/vmimage.subr b/release/tools/vmimage.subr
--- a/release/tools/vmimage.subr
+++ b/release/tools/vmimage.subr
@@ -83,6 +83,7 @@
 	if [ "${VMFS}" = zfs ]; then
 		echo "zfs_enable=\"YES\"" >> ${DESTDIR}/etc/rc.conf
 		echo "zpool_reguid=\"zroot\"" >> ${DESTDIR}/etc/rc.conf
+		echo "zpool_upgrade=\"zroot\"" >> ${DESTDIR}/etc/rc.conf
 	fi
 
 	if ! [ -z "${QEMUSTATIC}" ]; then