Abstract: A locking clip is disclosed for use with modular circuit packs that mount in mounting racks, and the insertion and extraction of circuit packs from a mounting rack is facilitated using a lever that is attached to the face plate of each circuit pack. When the novel locking clip is installed in a hole through the lever it is difficult to be seen and can only be removed with tweezers or similar small grasping tool. When in place the locking clip blocks the normal operation of the lever and the circuit pack cannot be removed from the mounting rack. Removal of the locking clip permits the lever to be operated normally to remove a circuit pack from the mounting rack.