Abstract: The invention is a positive lockout means for circuit breakers in an electrical distribution box wherein a central bar extends from top to bottom of the box between the arrays of circuit breakers. The bar has an array of bores extending into the bar from the top side of the distribution. Rod-like locking elements having a configuration which permits one end of the locking element to pass into a bore in a circuit breaker actuator while the other end is inserted in a bore in the bar to prevent movement of the actuator element so secured. Positive lockout is provided by a cover plate which is positively secured in position over the central bar.