The invention concerns a method for locking the jointing of a plastic tube (4) on a connecting piece (1), characterised in that it consists in the following: selecting a connecting piece (1) with external ring-shaped bulges (2, 3), causing at least an elastic deformation of a ring-shaped portion of the tube to force it into at least one ring-shaped recess (3) of the connecting piece (1) by applying under pressure a fluid material capable of being solidified around the tube portion and blocking the tube thus deformed on the connecting piece by bringing about the solidification of the material applied under pressure.