The study addresses the problem of liability for failure to report a crime of sexual abuse of minors, committed before the entry into force of the Act of 23 March 2017 amending the Act – Criminal Code, the Act on Proceedings in Ju-venile Cases, and the Act – Code of Criminal Procedure. It provides a solution to the problem that in the period from 23 July 2017 to 1 July 2022 (issuance of resolution I KZP 5/22), prosecutors’ offices, by definition, did not initiate pro-ceedings for offences under Article 240(1) of the Criminal Code involving fai-lure to report offences defined in Article 200 of the Criminal Code of which the perpetrator became reliably aware before 13 July 2017. The author ponders the question whether it is possible to consider that the limitation period was interrupted between 23 July 2017 and 1 July 2022, and concludes that under special conditions it is possible. As an aside to the main argument, the author refers to the constitutionality of retroactive extension of the limitation periods for punishability and for execution of the sentence.