A sensor system comprising optoelectronic distance sensors for monitoring a hazard zone at a movable machine part having at least one protected field, wherein the optoelectronic distance sensors are arranged in annular form in a first ring at the movable machine part, wherein a tool is arranged at the movable machine part, and wherein the optical axes of the distance sensors each have an acute angle tangentially to the annular shape or the distance sensors are rotatably arranged at the ring.