A liquefied gas fuel feeding system for an internal combustion piston engine comprising: a tank configured to store fuel in cryogenic conditions, which when in use comprises a liquid gas space (14.1) having a surface (14.2) and an ullage space (14.3) above the surface (14.2); a fuel supply line arranged to extend from the tank to the internal combustion piston engine , the fuel supply line comprising successively a first line section (16.1) and a second line section 16.2), wherein the first line section (16.1) is configured to receive liquefied gas from the tank , and comprises a liquid fuel pump configured to raise the pressure of liquefied gas to a predetermined first pressure and a gas evaporator configured to evaporate the liquefied gas into gaseous form at the first pressure; and wherein the second line section (16.2) is configured to receive gaseous gas from the gas evaporator , the second line section (16.2) comprising a gas valve unit configured to open or close the flow connection between the gas evaporator and the internal combustion piston engine ; the liquefied gas fuel feeding system is provided with a return line extending from the second line section (16.2) to the tank , the return line opening into the ullage space (14.3) of the tank and being provided with a first pressure relief valve configured to open when pressure in the second line section (16.2) exceeds a first set pressure, characterized in that , the liquefied gas fuel feeding system comprises a conduit configured to provide a flow connection between the second line section (16.2) and the ullage space of the tank , and that the conduit is provided with a valve member , the conduit extends from the second line section (16.2), to the return line , to a location between the first pressure relief valve and the tank , which conduit is at least partly parallel to the first pressure relief valve and the valve member is parallel to the first pressure relief valve . a tank configured to store fuel in cryogenic conditions, which when in use comprises a liquid gas space (14.1) having a surface (14.2) and an ullage space (14.3) above the surface (14.2); a fuel supply line arranged to extend from the tank to the internal combustion piston engine , the fuel supply line comprising successively a first line section (16.1) and a second line section 16.2), wherein the first line section (16.1) is configured to receive liquefied gas from the tank , and comprises a liquid fuel pump configured to raise the pressure of liquefied gas to a predetermined first pressure and a gas evaporator configured to evaporate the liquefied gas into gaseous form at the first pressure; and wherein the second line section (16.2) is configured to receive gaseous gas from the gas evaporator , the second line section (16.2) comprising a gas valve unit configured to open or close the flow connection between the gas evaporator and the internal combustion piston engine ; the liquefied gas fuel feeding system is provided with a return line extending from the second line section (16.2) to the tank , the return line opening into the ullage space (14.3) of the tank and being provided with a first pressure relief valve configured to open when pressure in the second line section (16.2) exceeds a first set pressure, characterized in that , the liquefied gas fuel feeding system comprises a conduit configured to provide a flow connection between the second line section (16.2) and the ullage space of the tank , and that the conduit is provided with a valve member , the conduit extends from the second line section (16.2), to the return line , to a location between the first pressure relief valve and the tank , which conduit is at least partly parallel to the first pressure relief valve and the valve member is parallel to the first pressure relief valve . <EOS>