An example gusset for attaching a rear bumper assembly to a vehicle has a first attachment portion configured to attach to the bumper reinforcement bracket and the lower back panel of the vehicle, a second attachment portion configured to attach to the rear side member of the vehicle, and an angled portion presenting an oblique surface to a rear impactor to the vehicle. A pair of side portions are interconnected and spaced apart by the second attachment portion, and each side portion has an angled edge adjacent the angled portion.