Abstract: The invention is directed to an arrangement for correcting the position of a laser beam guided by means of an articulated optical system. This system includes a position-sensitive detector at its output end for generating a signal which is passed to an adjustable mirror arranged on the input end. The adjustable mirror compensates for an excursion of the laser beam occurring as a result of faults in the guide means and bearings of the articulated arm. Prior to entering the articulated optical system, the laser beam or parallelly guided pilot beam is modulated with respect to the beam direction with a small amplitude by another adjustable mirror. The detector signal component corresponding to the modulation frequency is passed to an electronic circuit which determines the directional relationships between the excursion of the laser beam at the output of the articulated arm and the follow-up movement of the adjustable mirror for deflecting the beam.