In its judgment of 22 March 2022, the Court of Justice of the European Union (CJEU) provided an answer to the preliminary questions referred to it by the Brussels Court of Appeal regarding application of the non bis in idem principle in the context of proceedings against bpost carried out by both the Belgian Competition Authority and the Belgian Institute for Postal Services and Telecommunications. According to the CJEU, the non bis in idem principle applies in the event of a duplication of proceedings and penalties under sectoral rules and competition law. This judgment is particularly interesting in that the CJEU decided to depart from its previous case-law, thereby following the numerous suggestions made in that regard by several Advocate Generals. This novelty is however mitigated as the CJEU added that such duplication of proceedings could be accepted under certain precisely defined conditions, including the respect of the principle of proportionality.