This note discusses the distinction between international and non-international armed conflicts in the prosecution of war crimes before the International Criminal Court. It analyses the international humanitarian law applicable to both kinds of conflict, and the way in which the International Criminal Tribunal for the former Yugoslavia succeeded in prosecuting war crimes committed in non-international armed conflicts. It also studies the two war crimes regimes provided for in the Rome Statute of the International Criminal Court. The note then examines how Pre-Trial Chamber I dealt with this issue in its Decision on the confirmation of charges against Thomas Lubanga Dyilo and the problems it faced in doing so. It concludes with a plea for the abolition of the distinction between international and non-international armed conflicts with respect to war crimes in the Rome Statute of the International Criminal Court.