Just as some were getting ready to uncork bottles of champagne in celebration of the first anniversary of the enlargement of the European Union with ten member states, the Polish Constitutional Tribunal delivered an important judgment assessing the conformity of provisions of the Penal Procedure Code, transposing the European Arrest Warrant with the Polish Constitution. In the decision, which potentially has effects beyond the Polish legal system, the Tribunal annulled the transposing legislation (with a delay of 18 months) because it infringed Article 55(1), which states that ‘The extradition of a Polish citizen shall be prohibited’.