An assembly that includes an accessory gearbox (AGB) and a tank for a liquid lubricant for a turbojet engine. The AGB includes a gear connected to parallel shafts for mechanically driving accessories. The assembly includes a housing with two compartments and a partition perpendicular to the shafts for separating the compartments, a compartment defining the accessory gearbox and a compartment defining the liquid tank. The assembly can be compact and easily manufactured.