A box with two side panels, a front panel, a rear panel and at least one opening has two side flaps extending the side panels and a closure flap extending the rear panel. The closure flap has a tongue with a projecting abutment-forming surface. Each of the side flaps have cutout areas designed to interface with the tongue of the closure flap in such a manner as to facilitate insertion of the tongue between the front panel and the side flaps and resist removal of the tongue once insertion is completed.