diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c
index 1cf5ac09edcb..bec903e98db0 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -602,6 +602,9 @@ ieee802154_setup_sdata(struct ieee802154_sub_if_data *sdata,
                sdata->dev->needs_free_netdev = true;
                sdata->dev->netdev_ops = &mac802154_monitor_ops;
                wpan_dev->promiscuous_mode = true;
+
+               mutex_init(&sdata->sec_mtx);
+               mac802154_llsec_init(&sdata->sec);
                break;
        default:
                BUG();