The paper presents the issue of denunciation of international treaties, which contain no provisions on termination. Article 56 of the Vienna Convention on the Law of Treaties, adopted in 1969, covering the presumption against denunciation from treaties that lack a withdrawal or denunciation clause, specifies two exceptions to the general rule. They are defined in rather abstract terms, resulting in enormous difficulties with their practical application. The lack of clarity of the wording of Article 56 provides for the need to inquire into the matter to identify the concepts, reliance on which will make it possible to avoid unjustified references to the Article in question.