Clasp with unfolding buckle for wristlet, having: an inside blade (3), two outside blades (1) forming an articulated shank with the inside blade, two push-pieces (7) capable of being actuated transversely against the action of an elastic element (9) for unlocking the clasp, at least one stopping (11) connected removably to said push-piece (7) for limiting the amplitude of displacement of said push-piece along at least one axis.