A filler coupling for a pressurized gas receptacle designed to interact with a packaging connector in order to allow said receptacle to be filled, the coupling comprising a body defining an internal filler circuit between an upstream end adapted to be capable of connecting to a packaging connector and a downstream end adapted to be capable of connecting to a receptacle, the coupling comprising an isolation valve that is capable of moving relative to a seat between an upstream position capable of closing the internal filler circuit and a downstream position capable of opening the internal filler circuit, said isolation valve adapted to be moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being capable of moving relative to the body between an upstream position capable of closing the upstream end of the internal filler circuit and a downstream position capable of closing opening the internal filler circuit upstream end, said dust-prevention valve capable of closure by being moved to its upstream position by a return member, wherein the dust-prevention valve comprises a filter interposed on the path of at least a portion of the internal filler circuit, the filter being adapted to move with the dust-prevention valve.