18 Such is the certain and safe doctrine of the Church. If, however, the putting of it into practice should cause scandal to some of the faithful, it will be your duty, Venerable Brethren, to enlighten them carefully and exactly. If, after you have performed this office of explanation and persuasion, according to these Our directions, anyone should cling stubbornly to his own false opinion, let him know that he can hardly escape the reproach of disobedience and obstinacy.
Source: Acerba Animi (Vatican.va)