A toner cartridge according to one example embodiment includes a first positioning slot positioned on a first side of a housing of the toner cartridge for receiving a first corresponding positioning rib in an image forming device for defining an axial position of a photoconductive drum relative to the image forming device when the toner cartridge is installed in the image forming device. A second positioning slot is positioned on a second side of the housing for receiving a second corresponding positioning rib in the image forming device for defining an axial position of a developer roll relative to the image forming device when the toner cartridge is installed in the image forming device. The first and second positioning slots extend upward from a bottom of the housing near a longitudinal end of the housing.