A fastening system for attaching a structural element (5, 2) to a profile rail (3, 50) by means of a nailed joint, said fastening system comprising said profile rail, which comprises: a first flange portion (8; 51) for interaction with the structural element (5; 2); a second flange portion (9; 55) opposite to the first flange portion (8; 51); and a web portion (10; 53) interconnecting the flange portions (8, 9; 51, 53) and extending between the flange portions (8, 9; 51, 53), wherein the first flange portion (8; 51) exhibits a first, external surface for interaction with the structural element, and a second, internal surface facing toward the second flange portion, and wherein the second flange portion (9; 55) exhibits a first, external surface and a second, internal surface facing toward the first flange portion (8; 51), wherein the fastening system comprises at least one fastening means (21, 28, 32) comprising a first fastening means portion (22, 33; 52), a second fastening means portion (23, 34; 54) and at least one connecting portion (24, 35, 36, 37; 53) supporting and connecting the fastening means portions (22, 23; 33, 34; 52, 54) to each other, wherein said fastening means (21, 28, 32) is disposed in the profile rail (3, 50) so that the first fastening means portion (22, 33, 52) abuts against, or is at least disposed in close proximity to, the internal surface of the first flange portion (8, 51), and so that second fastening means portion (23, 34; 54) abuts against, or is at least disposed in close proximity to, the internal surface of the second flange portion (9, 55), wherein said first fastening means portion (22, 33; 52) forms a fastener for a nail which passes through the structural element (5, 2), the first flange portion (8; 51) and holds to the first fastening means portion (22, 33; 52) to form the nailed joint, characterized in that the at least one fastening means is formed from a folded or bent steel plate having a thickness of 0.7-1.5 mm. a first flange portion (8; 51) for interaction with the structural element (5; 2); a second flange portion (9; 55) opposite to the first flange portion (8; 51); and a web portion (10; 53) interconnecting the flange portions (8, 9; 51, 53) and extending between the flange portions (8, 9; 51, 53), wherein the first flange portion (8; 51) exhibits a first, external surface for interaction with the structural element, and a second, internal surface facing toward the second flange portion, and wherein the second flange portion (9; 55) exhibits a first, external surface and a second, internal surface facing toward the first flange portion (8; 51), wherein the fastening system comprises at least one fastening means (21, 28, 32) comprising a first fastening means portion (22, 33; 52), a second fastening means portion (23, 34; 54) and at least one connecting portion (24, 35, 36, 37; 53) supporting and connecting the fastening means portions (22, 23; 33, 34; 52, 54) to each other, wherein said fastening means (21, 28, 32) is disposed in the profile rail (3, 50) so that the first fastening means portion (22, 33, 52) abuts against, or is at least disposed in close proximity to, the internal surface of the first flange portion (8, 51), and so that second fastening means portion (23, 34; 54) abuts against, or is at least disposed in close proximity to, the internal surface of the second flange portion (9, 55), wherein said first fastening means portion (22, 33; 52) forms a fastener for a nail which passes through the structural element (5, 2), the first flange portion (8; 51) and holds to the first fastening means portion (22, 33; 52) to form the nailed joint, characterized in that the at least one fastening means is formed from a folded or bent steel plate having a thickness of 0.7-1.5 mm.