A toner cartridge according to one example includes first and second alignment guides that extend outward from a first side and a second side of the toner cartridge, respectively, for positioning the toner cartridge. The first and second alignment guides define a pivot axis about which the toner cartridge is pivotable relative to an imaging unit when the toner cartridge is installed on the imaging unit. An engagement member is positioned on a rear of the toner cartridge for receiving a bias force for biasing the toner cartridge about the pivot axis when the toner cartridge is installed on the imaging unit. The engagement member is positioned next to the bottom of the housing. The engagement member includes an angled contact surface that faces upward and rearward for contacting a corresponding hold-down on the imaging unit when the toner cartridge is installed on the imaging unit.