Machine tool for machining of a rotating workpiece, comprising a tool drive, a workpiece drive for rotatably driving the workpiece, a tool rotationally driven by the tool drive in synchronization with the workpiece for producing a toothing on the workpiece, rotation transmitters for determining rotational condition of the tool and the workpiece, respectively, an electronic control for keeping the workpiece drive and the tool drive in synchronization by respectively associated ones of the rotation transmitters. A positioning motor is associated with one of the two drives for influencing the position of the phases of the two drives, and a sensor element provided in association with one of the two rotation transmitters is rotatably adjustable with respect to a stator of a corresponding one of the drives.