The invention relates to a device for fixing a push element, in particular a drawer box (4) to a rail (5) of a pull-out guide (3), said device comprising a clamping mechanism with a receptacle (20), into which a web-shaped holding part (12) can be inserted, wherein a self-locking clamping element (25) is provided at the receptacle (20), by which the holding part (12) is secured in a clamping manner against being pulled out. In this way, a particularly stable fixation of the drawer box (4) to a pull-out guide (3) can be achieved.