A coupling member for interconnecting two containers stacked one above the other, particularly on board ships, having a first coupling projection that can be hooked into a corner fitting of one container and pre-locked there, and a second coupling projection that can be coupled to a corner fitting of the other container, and having an actuating member by means of which the second coupling projection can be switched between an automatic position, in which the containers lock and unlock fully automatically during loading and unloading, and a second position, in which the containers must be manually unlocked by an operator during unloading, wherein the second coupling projection is moved under pre-tension into the automatic position or the second position and can be moved to the respective other position by means of the actuating member, counter to the pre-tensioning force is provided.