A daytime running lamp for being retrofitted on a road vehicle, comprising a reflector with a reflective surface for reflecting light in a general direction of illumination and a plurality of light sources arranged in a pattern having an extension along a horizontal axis. The light emitted by the plurality of light sources has directional components in two opposite horizontal directions along the horizontal axis and a directional component in a vertical direction perpendicular to the horizontal axis. The reflective surface has a curvature such that the directional component in the vertical direction is directed towards the general direction of illumination, and the directional component in at least one of the horizontal directions upon reflection in the reflective surface is substantially unchanged by the reflection.