A developer cartridge for containing a developer and for delivering the developer to a developer hopper of an electro-photographic machine. A developer containment portion includes a first portion having an at least partially closed volume configured to contain the developer and a second portion adjacent the first portion and having an opening configured to deliver the developer the developer hopper. A sealing gasket is disposed adjacent the second portion of the developer containment portion and surrounds at least a portion of a circumference of the opening. A first cover is disposed adjacent the second portion of the developer containment portion and is positionable between an pen position for delivery of the developer and a closed position for preventing delivery of the developer. The sealing gasket contacts the first cover to prevent undesired leakage of the developer therebetween.