A lightning current transfer assembly (2) for a wind turbine (1) is arranged to transfer lightning current from a wind-turbine part (8) to another part (8) rotatable relative to it. The assembly comprises at least one electric contact arrangement (11′, 11″) comprising complementary contact members (12a′, 12b′, 12a″, 12b″) which provide electric connection by mechanically contacting each other while being movable relative to each; a spark gap (4) connected in series with the movement-enabling contact arrangement (11′, 11″); and a spark-gap-bridging resistance (6) connected parallel to the spark gap (4). Thereby, the assembly provides at least two alternative current paths: (i) a lightning current path across the at least one electric contact arrangement and the spark gap, and (ii) a permanent-discharge current path across the at least one electric contact arrangement and through the spark-gap-bridging resistance.