Any person domiciled in Luxembourg who is sued in a court of another Contracting State pursuant to Article 5(1) may refuse to submit to the jurisdiction of that court. If the defendant does not enter an appearance the court shall declare of its own motion that it has no jurisdiction.

An agreement conferring jurisdiction, within the meaning of Article 17, shall be valid with respect to a person domiciled in Luxembourg only if that person has expressly and specifically so agreed.