A sealing device for a container comprising a circular cap designed to seal the neck of the container and a cover made from a synthetic material capable of covering both the neck and the cap fitted on the neck, the cover being provided with means for locking onto the neck, the cover being in one piece and comprising a skirt capable of radially surrounding a collar of the neck of the container, and an annular portion provided with a central opening allowing permanent access to the cap, and the skirt having at least two jamming areas for jamming the cap and, on the inner radial face thereof between the two jamming areas, a release area with a diameter strictly greater than the minimum unstressed diameter of the cap.
