diff --git a/tests/sys/net/Makefile b/tests/sys/net/Makefile
--- a/tests/sys/net/Makefile
+++ b/tests/sys/net/Makefile
@@ -6,6 +6,7 @@
 BINDIR=		${TESTSDIR}
 
 ATF_TESTS_C+=	if_epair
+ATF_TESTS_SH+=	if_epair_test
 ATF_TESTS_SH+=	if_bridge_test
 TEST_METADATA.if_bridge_test+=	required_programs="python"
 ATF_TESTS_SH+=	if_clone_test
diff --git a/tests/sys/net/if_epair_test.sh b/tests/sys/net/if_epair_test.sh
new file mode 100644
--- /dev/null
+++ b/tests/sys/net/if_epair_test.sh
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# Copyright (c) 2023 Rubicon Communications, LLC (Netgate)
+#
+# 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.
+
+. $(atf_get_srcdir)/../common/vnet.subr
+
+atf_test_case "pcp" "cleanup"
+pcp_head()
+{
+	atf_set descr 'Test PCP over if_epair. PR#270736'
+	atf_set require.user root
+}
+
+pcp_body()
+{
+	vnet_init
+
+	j="if_epair_test_pcp"
+
+	epair=$(vnet_mkepair)
+
+	vnet_mkjail ${j}one ${epair}a
+	vnet_mkjail ${j}two ${epair}b
+
+	jexec ${j}one ifconfig ${epair}a 192.0.2.1/24 pcp 3 up
+	jexec ${j}two ifconfig ${epair}b 192.0.2.2/24 up
+
+	atf_check -s exit:0 -o ignore \
+	    jexec ${j}one ping -c 1 192.0.2.2
+
+	# Now set a different PCP. This used to lead to double tagging and failed pin.
+	atf_check -s exit:0 -o ignore \
+	    jexec ${j}one ping -C5 -c 1 192.0.2.2
+}
+
+pcp_cleanup()
+{
+	vnet_cleanup
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case "pcp"
+}