diff --git a/tests/sys/netinet6/mld.sh b/tests/sys/netinet6/mld.sh
index 034d5945ae20..80b7117c3717 100755
--- a/tests/sys/netinet6/mld.sh
+++ b/tests/sys/netinet6/mld.sh
@@ -1,89 +1,129 @@
 # $FreeBSD$
 #-
 # SPDX-License-Identifier: BSD-2-Clause
 #
 # Copyright (c) 2019 Netflix, Inc.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 . $(atf_get_srcdir)/../common/vnet.subr
 
 atf_test_case "mldraw01" "cleanup"
 mldraw01_head() {
 
 	atf_set descr 'Test for correct Ethernet Destination MAC address'
 	atf_set require.user root
 	atf_set require.progs scapy
 }
 
 mldraw01_body() {
 
 	ids=65533
 	id=`printf "%x" ${ids}`
 	if [ $$ -gt 65535 ]; then
 		xl=`printf "%x" $(($$ - 65535))`
 		yl="1"
 	else
 		xl=`printf "%x" $$`
 		yl=""
 	fi
 
 	vnet_init
 
 	ip6a="2001:db8:6666:0000:${yl}:${id}:1:${xl}"
 	ip6b="2001:db8:6666:0000:${yl}:${id}:2:${xl}"
 
 	epair=$(vnet_mkepair)
 	ifconfig ${epair}a up
 	ifconfig ${epair}a inet6 ${ip6a}/64
 
 	jname="v6t-${id}-${yl}-${xl}"
 	vnet_mkjail ${jname} ${epair}b
 	jexec ${jname} ifconfig ${epair}b up
 	jexec ${jname} ifconfig ${epair}b inet6 ${ip6b}/64
 
 	# Let IPv6 ND do its thing.
 	#ping6 -q -c 1 ff02::1%${epair}a
 	#ping6 -q -c 1 ${ip6b}
 	sleep 3
 
 	pyname=$(atf_get ident)
 
 	atf_check -s exit:0 $(atf_get_srcdir)/mld.py \
 		--sendif ${epair}a --recvif ${epair}a \
 		--src ${ip6a} --to  ${ip6b} \
 		--${pyname}
 }
 
 mldraw01_cleanup() {
 
 	vnet_cleanup
 }
 
+atf_test_case "pr233683" "cleanup"
+pr233683_head() {
+
+	atf_set descr 'Test for PR233683'
+	atf_set require.user root
+}
+
+pr233683_body() {
+	j="mld:pr233683"
+
+	vnet_init
+
+	epair=$(vnet_mkepair)
+
+	vnet_mkjail ${j}a ${epair}a
+	jexec ${j}a ifconfig ${epair}a inet6 2001:db8::1/64 up
+	sleep 5
+
+	jexec ${j}a ifconfig ${epair}a inet6 2001:db8::1/64
+
+	vnet_mkjail ${j}b ${epair}b
+	jexec ${j}b ifconfig ${epair}b inet6 2001:db8::2/64 up
+
+	# Allow DAD to run
+	sleep 5
+
+	# Debug output. If the bug is present we'd expect to not see a
+	# membership for ff02::1:ff00:1
+	jexec ${j}a ifmcstat -i ${epair}a
+	jexec ${j}a ifconfig ${epair}a
+
+	atf_check -s exit:0 -o ignore \
+	    jexec ${j}b ping -6 -c 1 2001:db8::1
+}
+
+pr233683_cleanup() {
+
+	vnet_cleanup
+}
 atf_init_test_cases()
 {
 
 	atf_add_test_case "mldraw01"
+	atf_add_test_case "pr233683"
 }
 
 # end