Toner cartridge latching

A first replaceable unit is provided for use with a second replaceable unit in an electrophotographic image forming device. The first replaceable unit includes a latch movable between a latching position for latching the first replaceable unit to the second replaceable unit and an unlatching position for permitting the first replaceable unit to separate from the second replaceable unit. The latch is positioned to contact a latch catch on the second replaceable unit in order to prevent the first replaceable unit from separating from the second replaceable unit when the first replaceable unit is mated with the second replaceable unit and the latch is in the latching position. The latch includes a cam follower surface for contacting a camming surface on the second replaceable unit during mating of the first replaceable unit with the second replaceable unit to cause the latch to move toward the latching or unlatching position.