Abstract: A device enabling a fluid dispenser to operate both in the upside-down position and in the rightway-up position, the dispenser comprising a fluid tank, and a dispenser member having an inlet and a dip tube, said device having a chamber in communication with said inlet of the dispenser member, said chamber having a top inlet and a bottom inlet that are selectively closable by respective top and bottom check valves, the top check valve having a moving valve element suitable for closing the top inlet of the chamber in the rightway-up position, wherein the bottom check valve has a moving valve element that floats, being of a density that is lower than the density of the fluid, and being adapted to close the bottom inlet of the chamber in the upside-down position when the chamber is filled with the fluid.