Abstract: A locking device with a ratchet to secure two or more screw-action connectors for axial rotation in one direction and to allow rotation of the connectors in an opposite axial direction. The locking device having two rings with teeth on the outer side, each ring to fit around one of the connectors, and assembled with a body with teeth on the inner side, enclosing the two rings, where the mating teeth of ring and body generate the ratchet, to allow ratcheting the ring in one axial direction, and blocking the axial rotation of the ring and connector in the opposite direction.