The invention provides child-resistant closures comprising: an inner closure part (100) carrying an internal screw thread (106) for screw threaded engagement with the neck of a container; an outer closure part (200) retained on the inner closure part (100); a first set of castellations (126) on the inner part (100); a complementary second set of castellations (212) on the outer part (200); a set of resilient blades (216) on one of the inner or outer part to hold the inner and outer parts (100, 200) apart so that the castellations (126, 212) do not engage unless an axial compressive force is applied between the inner and outer parts; and ratchet projections (120) on the other of the inner or outer part adapted to engage the resilient blades (216) only when the outer part is rotated in the screwing-down direction. The improvements comprise means to reduce the transfer of unscrewing torque from the outer closure part (200) to the inner closure part (100) when a bending moment is applied between the inner and outer closure parts and the outer part (200) is rotated in an unscrewing direction. The preferred means include: (i) radial chamfering of one or both sets of castellations (126, 212); (ii) means to reduce rocking of the outer closure part on the inner closure part, especially a cylindrical projection (214) on one of the inner or outer part slidably received in a cylindrical socket (130) on the other of the inner or outer parts, the projection (214) and socket (130) being coaxial with the rotational axis of the closure; (iii) the provision of an integral reinforcing rib (220) on the resilient blades (216); and (iv) the provision of lubricant between abutting surfaces of the inner and outer closure parts.