A headlamp for vehicles having a projection module containing a first light source for generating a first light bundle, a reflector assigned to the first light source, a lens, and an edge disposed in a focal plane for generating a low beam light distribution. The headlamp also includes a second light source for generating a second light bundle and an optics unit disposed between the lens and the second light source for generating a supplementary light distribution, such that by superimposing the supplementary light distribution and the low beam light distribution, a high beam light distribution is formed. The optics unit is formed by a flat waveguide having a light entry surface for receiving the second light bundle emitted from the second light source. The second light source is disposed in the proximity of the light entry surface, having a light exit surface, and flat sides extending between the light entry surface and the light exit surface, on which entering light can be conducted through total reflection. A light/dark border of the low beam light distribution is formed by the edge of the flat waveguide formed as the front outer edge, which connects the light exit surface and an upper flat side of the waveguide. The upper flat side of the flat waveguide is provided with a light blocking coating, such that an entry of light beams from the first light bundle striking the upper flat side is prevented.