A toner cartridge according to one embodiment includes a housing having a toner reservoir. An outlet port in fluid communication with the reservoir is positioned on a front of the housing near a first side of the housing. An interface gear is exposed on the front of the housing near a second side of the housing. A magnet is movable in response to rotation of the interface gear. An engagement member is positioned on an exterior of the top of the housing proximate the second side of the housing. The engagement member is aligned with a point in a path of movement of the magnet. The engagement member has a front surface that is unobstructed to contact and push a housing in the image forming device supporting a magnetic sensor to an operating position of the magnetic sensor during insertion of the toner cartridge into the image forming device.