A ring (10) for arranging around a valve body (21) of a fluid dispenser valve (20) that is mounted by means of a fastener capsule (50), such as a crimpable capsule, on a reservoir (1) containing fluid to be dispensed, said ring (10) being made as a single piece including at least one inner portion (100, 110) that co-operates with said valve body (21), and a radial flange (11) that forms a neck gasket that extends between the neck of the reservoir (1) and the fastener capsule (50).