Abstract: An assembly for a locking cap for containers with a threaded neck, having an inner cap, an intermediate cap, and an outer cap. The inner cap 1 has on its upper edge a circumferential knurl. The intermediate cap has on its inner face another knurl and on its top face. The outer cap has on its inner bottom face downwardly pointing projections 15. The knurl of the intermediate cap engages in the circumferential knurl of the inner cap. A container with this assembly can only be opened if pressure is applied to the top face of the outer cap.