A robotic work tool system (200) comprising a robotic work tool (100) and a beacon marker (280), said robotic work tool (100) comprising a beacon sensor (175) configured to sense a signal being transmitted by the beacon marker (280), said beacon marker (280) marking an area (270) around an obstacle (260) in a work area (205) in which said robotic work tool (100) is arranged to operate, wherein said robotic work tool is configured to determine a proximity to a beacon marker (280) and to adapt its operation accordingly.