A fastening system for fastening a lamp has at least one electrical source of radiant light, in place in a light system. Part of the lamp projects into an opening in the light system and is releasably connected thereto. At least three lugs take the form of electrical contacts and reference points in this case, and the areas of contact of the lug and lug-receptacle system are so arranged that, in the end position, their mating areas can be caused to mate in positive inter-engagement by an axially applied force.