The CJEU ruling in LM case (commonly known as Celmer) regarding the right to a fair trial in the context of European Arrest Warrant introduced a two-steps test aimed at verification of threats to judicial independence of issuing judicial authority. In consequence, CJEU introduced the national courts as legitimate actors in the ongoing rule of law debate. The major challenge, however, deals with the fact that courts will be obliged to verify the independence of other domestic courts. The paper discusses rulings (Celmer decided by the Irish High Court and by the Supreme Court; Lis & Ors v Regional Court In Warsaw; The Circuit Court of Warszawa-Praga v Maciejec), in which domestic courts applied Celmer test. The analysis covers how the defendants phrased the relevant arguments; how the court applied the Celmer test – both on the systemic and individual level; what was the outcome of the application.