A locking device for containers with a container lock housing and with a locking hook. The locking hook has a pivot axis, which is stationary relative to the container lock housing and which can pivot about the locking hook into a standby position and a locking position. An activation mechanism is included for the locking hook, which has a first actuating element and a second actuating element as well as a release mechanism. The first actuating element holds the locking hook in its standby position, while the second actuating element is configured such that it blocks and clamps the locking hook in its locking position. The release mechanism after the releasing acts on the first actuating element and/or on the second actuating element, which automatically brings about the clamping and blocking of the locking hook in its locking position by the second actuating element.