An electronic device is disclosed. The electronic device includes a device magnet designed to magnetically couple with an accessory device magnet. The electronic device further includes a display assembly and a magnetic field sensor configured to detect the accessory device magnet, thereby providing an indication that the accessory device is covering the display assembly. The electronic device further includes a shunt assembly designed to reduce the magnitude of the magnetic field of the device magnet, as determined by the magnetic field sensor, while allowing the magnetic field from the accessory device to sufficiently reach the magnetic field sensor. As such, the magnetic field sensor can be placed near the device magnet without triggering the magnetic field sensor. The electronic device may further include a microphone. Communication between the microphone and an integrated circuit can cease based on the magnetic field sensor detecting the accessory device magnet.