An agricultural harvester including a storage tank that includes a tank body and a tank cover assembly. The tank cover assembly has a travel state and an operational state. The tank cover includes a fabric wall element which is moveably connected to the tank body. In the operational state, the fabric wall element provides an upward extension of at least a part of the circumferential wall. In the travel state, the fabric wall element covers at least a part of the open top of the tank body. The fabric wall element includes a rigid area. The cover actuator assembly includes at least one cover actuator that is adapted to bring the tank cover assembly from the travel state into the operational state and vice versa, and to engage the fabric wall element at the rigid area.