Part 2 of Article 389.17 of the Criminal Procedure Code of the Russian Federation establishes a list of unconditionally significant violations of the norms of the criminal procedure law, the identification of which in a case entails the cancellation or change of the sentence in every case without exception. The range of these violations was determined by the legislator during the development of the Code of Criminal Procedure of the Russian Federation in 2001, and has not changed since then. However, the rules, violation of which can affect the quality of the sentence and lead to its cancellation in each case, have changed more than once. Including the norms governing the institution of returning the case to the prosecutor in accordance with Art. 237 of the Code of Criminal Procedure of the Russian Federation and determining the significance of this institution for the issuance of a legal, reasonable and fair sentence. In this regard, this article discusses the feasibility of expanding the list of unconditional grounds for canceling a sentence by including a violation associated with the failure of the court to take measures to return the criminal case to the prosecutor in accordance with Art. 237 of the Criminal Procedure Code of the Russian Federation, if there are grounds for that.