The invention relates to a device manufacturing method comprising exposing a substrate with a patterned beam of radiation formed by a reticle mounted on a displaceable reticle stage, wherein the method comprises the steps of determining a non-linear function for approximating a height and a tilt profile of a reticle surface with respect to the reticle stage and controlling a displacement of the reticle stage during exposure of the substrate in accordance with the non-linear function. The invention further relates to a lithographic apparatus and a computer program.