An optoelectronic sensor, comprising a first strip having transmitter elements and/or receiver elements, a second strip having transmitter elements and/or receiver elements, wherein the transmitter elements of one strip form transmitter/receiver pairs with receiver elements of the other strip for the formation of a protective field, and an evaluation unit for the evaluation of the received light of the receiver elements, wherein a light beam between the transmitter elements and receiver elements counts as interrupted when received light falls below a first lower switching threshold and as not interrupted when a first lower switching threshold is exceeded and wherein an object detection signal can be transmitted when at least one light beam is interrupted, characterized in that for the evaluation of the received light of at least one receiver element a second upper switching threshold is provided in the evaluation unit the value of which lies above the value of the first lower switching threshold, with a signal to indicate bypass light being given when the value of the received light lies above the second upper threshold.