This disclosure describes an extended closure sensor design for an electronic device. An electronic device (300) senses, with a magnetic sensor (306), an open or a closed position of the electronic device (300). A lid magnetic field is propagated through a ferromagnetic material (304) by a lid magnet (302) when a lid (310) or similar component of the electronic device (300) is in the closed position, thereby placing the lid magnetic field incident upon the magnetic sensor (306). In the open position, the lid magnetic field is materially absent and a bias magnet (308) causes a bias magnetic field to be incident upon the magnetic sensor (306).