This paper is a detailed study of the differences between the Montreal Convention 1971 (as amended by the 1988 protocol) and the Beijing Convention 2010, and between the Hague Convention 1970 and the Beijing Protocol 2010, which amends the latter convention. The broadened scope of criminalisation in the 2010 instruments and the newly defined forms of international crimes are discussed. This includes a commentary on the drawbacks of the existing treaties and on their reform. Shortfalls of the Beijing Convention and the Beijing Protocol are also pointed out. Additionally, the compatibility of Polish criminal law with the current international provisions and with the 2010 international instruments is considered. In both instances, specific amendments to national regulations are recommended.