Childproof safety cap has two opposite bead-like threads on its inner wall. Each thread has a widened end region, a stop surface thus being formed. The associated bottle has two opposite groove-like threads on a connecting piece of the bottle, each of which threads has a widened region in the end region, an undercut thus being formed in the groove by the widened region. When the safety cap is screwed on, the stop surfaces on the two bead-like threads hook in behind the undercuts on the groove-like threads. The stop surfaces can be released from each other only if the safety cap is pressed down toward the bottle onto the connecting-piece neck. Connecting-piece neck forms a slipping surface that conically expands downwards. The safety cap can then be unscrewed while simultaneously being rotated.