The invention relates to an optical sensor with collision protection for a measurement machine, in particular for a coordinate measurement machine. The optical sensor comprises a sensor-side coupling part for mechanically and optically connecting to the measurement machine, and a sensor element. According to the invention, the sensor comprises a sensor protective coupling as collision protection, said protective coupling comprising a coupling part on the measurement machine side and a coupling part on the sensor element side, wherein a fiber optic cable is routed between the coupling parts of the sensor protective coupling and wherein a fiber optic cable protection element surrounds the fiber optic cable, wherein the ends of the fiber optic cable protection element are fastened to the associated coupling part of the sensor protective coupling.