Article 874

An absolute condition not to contract a first or subsequent marriage shall be considered as not written unless such condition has been imposed on the widow or widower by the deceased spouse, or by the latter's ascendants or descendants.

Nevertheless, the right of usufruct, or an allowance or some personal prestation may be devised or bequeathed to any person for the time during which he or she should remain unmarried or in widowhood. (793a)