Double door system (1) comprising an understriking door leaf (2), an overstriking door leaf (3), a first door operator (11) adapted to move the understriking door leaf (2) between an open and a closed position, a second door operator (12) adapted to move the overstriking door leaf (3) between an open and a closed position and a mechanical brake arrangement (400), wherein the understriking door leaf (2) should be closed before the overstriking door leaf (3) to close the double door, and wherein the mechanical brake arrangement (400) is arranged to brake the movement of the overstriking door leaf (3). Mechanical brake arrangement (400) for controlling the movement of one of the door leafs of a double door system. Door operator system (10) comprising a first door operator (11), a second door operator (12) and a mechanical brake arrangement (400).