Light module of a lighting and/or signalling device for a motor vehicle, comprising: at least one light source positioned on a source support an optical element comprising an input face which receives light rays emitted by said at least one light source and is positioned facing the latter a frame supporting the optical element and fastened to said source support the optical element having at least one stud having a free end projecting towards the source support, said at least one stud being made of the same material as the optical element and being in direct or indirect contact with the source support when the light module is assembled, and in that the optical element comprises a plurality of optical guides (33, 34), each comprising an input face (33a, 34a) forming said input face of the optical element, and in that the optical element also comprises at least as many optical guides as there are light sources, each of the light sources being associated with an optical guide (33, 34) so that light rays emitted by each light source enter the optical element through the input face (33a, 34a) of the optical guide (33, 34) with which it is associated, the frame comprising a base by means of which it is in contact with said source support, and the orthogonal projection of the free end of at least one of the studs onto a straight line D perpendicular to the plane Ta tangent to said base is located further downstream, in the direction of the base, than the projection of that input face (33a, 34a) of the optical guide (33, 34) that is located furthest downstream in this same direction from among all the projections of the input faces (33a, 34a) of the optical guides (33, 34), and before the assembly formed by the optical element and the frame is mounted on the source support, each stud is secant to the plane Ta tangent to the base, characterized in that the coefficient of expansion of the frame is much lower than the coefficient of expansion of the studs. at least one light source positioned on a source support an optical element comprising an input face which receives light rays emitted by said at least one light source and is positioned facing the latter a frame supporting the optical element and fastened to said source support the optical element having at least one stud having a free end projecting towards the source support, said at least one stud being made of the same material as the optical element and being in direct or indirect contact with the source support when the light module is assembled, and in that the optical element comprises a plurality of optical guides (33, 34), each comprising an input face (33a, 34a) forming said input face of the optical element, and in that the optical element also comprises at least as many optical guides as there are light sources, each of the light sources being associated with an optical guide (33, 34) so that light rays emitted by each light source enter the optical element through the input face (33a, 34a) of the optical guide (33, 34) with which it is associated, the frame comprising a base by means of which it is in contact with said source support, and the orthogonal projection of the free end of at least one of the studs onto a straight line D perpendicular to the plane Ta tangent to said base is located further downstream, in the direction of the base, than the projection of that input face (33a, 34a) of the optical guide (33, 34) that is located furthest downstream in this same direction from among all the projections of the input faces (33a, 34a) of the optical guides (33, 34), and before the assembly formed by the optical element and the frame is mounted on the source support, each stud is secant to the plane Ta tangent to the base, characterized in that the coefficient of expansion of the frame is much lower than the coefficient of expansion of the studs.