Abstract: Blocking device for a lid (4) on a waste container, the device (6) comprising a hook (1) the underside of which being arranged above the hinge part (7) of the lid when the lid (4) is closed, the hook (1) being arranged on an elastic bar (2) being adapted to be bent when the hinge part (7) is pressed towards the underside of the hook (1), and the upper side of the hook (1) is inclined to receive and hold the weight of the hinge part (7), however allow the hinge part (7) to pass by the hook (1) as the bar (2) is bent when the hinge part (7) is pressed against the hook (1).