A gas turbine engine fuel supply assembly which includes a fuel manifold mounted to a casing surrounding a combustor of the engine, and a plurality of fuel nozzles mounted to the fuel manifold. A mating interface between the fuel nozzles and the fuel manifold has at least one sealing element, and at least one aperture defined in the fuel nozzle proximate to the mating interface. The aperture is a non fuel conveying passage, and reduces conductive heat transfer to the sealing element by preventing a direct conductive heat transfer path between a hot region of the fuel nozzle and the sealing element.