diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index dfa9cedd27c8..57da67e2732d 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1951,6 +1951,9 @@ static int nl802154_add_llsec_devkey(struct sk_buff *skb, struct genl_info *info
 	struct ieee802154_llsec_device_key key;
 	__le64 extended_addr;
 
+	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)
+		return -EOPNOTSUPP;
+
 	if (!info->attrs[NL802154_ATTR_SEC_DEVKEY] ||
 	    nla_parse_nested(attrs, NL802154_DEVKEY_ATTR_MAX,
 			     info->attrs[NL802154_ATTR_SEC_DEVKEY],