Abstract: A locking apparatus for locking the doors of a cargo container, such as the rear doors of a trailer, is disclosed. The locking assembly may include a second tubular member that telescopes and slides within a first tubular member and an L-shaped assembly mounted on or near the ends of the respective first and second tubular members. The locking apparatus may be placed in a perpendicular fashion between the securing rods of the doors of a cargo container, and the tubular members may be slidably telescoped until the L-shaped assemblies substantially fill the spaces between the cam pins of the securing rods and the walls of the cam pin housings containing the cam pins when the securing rods are in a locked position. In this manner, the cam pins will be prevented from being removed from the cam pin housings, thereby preventing the securing rods from rotating, which in turn keeps the doors of the cargo container securely and tightly locked.