diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index f5b401c446ed..6aa872a19364 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -2304,10 +2304,10 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		 * We should propagate selected flags to the parent,
 		 * e.g., promiscuous mode.
 		 */
-		VLAN_XLOCK();
+		VLAN_SLOCK();
 		if (TRUNK(ifv) != NULL)
 			error = vlan_setflags(ifp, 1);
-		VLAN_XUNLOCK();
+		VLAN_SUNLOCK();
 		break;
 
 	case SIOCADDMULTI:
diff --git a/tests/sys/net/if_vlan.sh b/tests/sys/net/if_vlan.sh
index 96426254bb6d..e4c737121bdb 100755
--- a/tests/sys/net/if_vlan.sh
+++ b/tests/sys/net/if_vlan.sh
@@ -221,6 +221,34 @@ qinq_dot_cleanup()
 	vnet_cleanup
 }
 
+atf_test_case "qinq_setflags" "cleanup"
+qinq_setflags_head()
+{
+	atf_set descr 'Test setting flags on a QinQ device'
+	atf_set require.user root
+}
+
+qinq_setflags_body()
+{
+	vnet_init
+
+	epair=$(vnet_mkepair)
+
+	ifconfig ${epair}a up
+	vlan1=$(ifconfig vlan create)
+	ifconfig $vlan1 vlan 1 vlandev ${epair}a
+	vlan2=$(ifconfig vlan create)
+	ifconfig $vlan2 vlan 2 vlandev $vlan1
+
+	# This panics, incorrect locking
+	ifconfig $vlan2 promisc
+}
+
+qinq_setflags_cleanup()
+{
+	vnet_cleanup
+}
+
 atf_test_case "bpf_pcp" "cleanup"
 bpf_pcp_head()
 {
@@ -273,5 +301,6 @@ atf_init_test_cases()
 	atf_add_test_case "qinq_deep"
 	atf_add_test_case "qinq_legacy"
 	atf_add_test_case "qinq_dot"
+	atf_add_test_case "qinq_setflags"
 	atf_add_test_case "bpf_pcp"
 }