Two embodiments of a slope extension are disclosed herein for use with a vehicle restraint. In each embodiment, the vehicle restraint is adapted to releasably secure a parked trailer or other vehicle to an adjacent structure, such as a loading dock, and includes a carriage assembly which is adjustably mounted in proximity to the adjacent structure for movement relative to a roadway, and a restraining member which is operatively attached to the carriage assembly. In operation, each embodiment of the inventive slope extension interacts with the carriage assembly to avoid a “dead lock” condition wherein the carriage assembly is obstructed from moving downwardly toward the roadway.