An aspect of the present invention includes a method for patterning a workpiece covered at least partly with a layer sensitive to electromagnetic radiation by simultaneously using a plurality of exposure beams. In an example embodiment it is determined if any of the beams have an actual position relative to a reference beam which differs from its intended position. An adjustment of the exposure dose for a wrongly positioned beam is performed if said beam is printed at en edge of a feature. Other aspects of the present invention are reflected in the detailed description, figures and claims.