To prevent the developer housing of a toner cartridge from flexing and thereby causing toner leaks, one or more support ribs are added internally to the developer housing, near the developer roll opening to prevent housing flexure. The support rib is designed to not impede toner flow, or movement and installation of components within the cartridge (such as the agitator or other moving parts). The support rib may be formed integrally within the housing, or formed separately and then installed within housing.