Device for clamping together two parts of a sports article, including: a rectilinear notched tongue (6), integral with a first part of the sports article; a guide (30) integral with the second part of the sports article, said guide having two walls (33) between which said tongue (6) is able to slide; a pawl (40) articulated on the guide (30), capable of interacting with the notched tongue (6) in order to immobilize it in position relative to the guide (30); characterized in that it also includes a complementary piece (20) interacting with at least one part of the outer faces of the guide (30), and of which the portion located on the side with the opening of the guide (30) via which the tongue (6) is inserted includes two divergent walls (25, 26) which flare out and extend beyond the opening of the guide (30).