diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 29916f8cfdc395..b1c55db7376487 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -2138,6 +2138,9 @@ static int nl802154_add_llsec_seclevel(struct sk_buff *skb,
 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
 	struct ieee802154_llsec_seclevel sl;
 
+	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)
+		return -EOPNOTSUPP;
+
 	if (llsec_parse_seclevel(info->attrs[NL802154_ATTR_SEC_LEVEL],
 				 &sl) < 0)
 		return -EINVAL;