The present invention relates to a system and to a fastening of a rail on a substrate, with a guide plate for laterally guiding the rail that has a standing surface associated with the substrate, a support element to support the guide plate in the assembly position, a spring element supported on the guide plate and at least one spring arm for exerting a resilient holding force onto the foot of the rail, and a tensioning means for tensioning the spring element. The fastening can be assembled in that the support element has a support lug supported on the substrate in the assembly position to reach under the standing surface of the guide plate in a way that the guide plate is supported on the substrate via the support lug in the region where the guide plate and support lug overlap.