This invention relates to a guide for a vehicle seat belt securing a child safety seat in the vehicle. The belt guide comprises a body, a slot extending into the body from an edge thereof and having a longitudinal axis, the slot further extending through the body in a direction transverse to its longitudinal axis, and wherein the belt guide further comprises means adapted to permit movement of the belt lengthwise along the slot, and transversely through the slot in one direction, but not the other. An associated child safety seat comprising a guide is also disclosed.