Originally, when the European Economic Community was founded, the principle of procedural autonomy was one of the main rules regulating the relationship between the Community itself and Member States. While this principle is formally still in force, it has been the object of an interesting evolution which has happened in parallel to the evolution of another and complementary principle, the principle of effective judicial protection. The CJEU has often referred in combination to the two principles. Lately, however, the ECJ has referred to the principle of effective judicial protection in a new and broader sense. The paper is aimed at analyzing this most recent Luxemburg jurisprudence and, in particular, the case European Commission v. Republic of Polonia, C-619/18, in order of understand if this case law represents the beginning of a new season in the story of the principle of effective judicial protection.