System for locking two parts (2, 3) of a cable raceway, the system defining a reference axis and comprising a clip projecting from a wall of a first part, said clip having two portions: - a first portion, called the little portion, defined between two edges (21, 22) on either side of the reference axis, - a second portion, called the large portion, defined between two edges (24, 25) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (24, 25) of the large portion and the reference axis is greater than the distance between the edge (21, 22) of the little portion and the reference axis; the locking system further comprising an opening created in a wall of the second part, said opening having two portions: - a first portion, called the little portion, defined between two edges (38, 39) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (38, 39) of the little portion of the opening and the reference axis on one hand is greater than the distance between the edge (21, 22) of the little portion of the clip and the reference axis and, on the other hand, is less than the distance between the edge (24, 25) of the large portion of the clip and the reference axis; - a second portion, called the large portion, defined between two edges (41, 42) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (41, 42) of the large portion of the opening and the reference axis is greater than the distance between the edge (24, 25) of the large portion of the clip and the reference axis the first part further comprises a blocking tab projecting from the wall of the first part and in which the second part comprises a window created in the wall of the second part. - a first portion, called the little portion, defined between two edges (21, 22) on either side of the reference axis, - a second portion, called the large portion, defined between two edges (24, 25) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (24, 25) of the large portion and the reference axis is greater than the distance between the edge (21, 22) of the little portion and the reference axis; - a first portion, called the little portion, defined between two edges (38, 39) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (38, 39) of the little portion of the opening and the reference axis on one hand is greater than the distance between the edge (21, 22) of the little portion of the clip and the reference axis and, on the other hand, is less than the distance between the edge (24, 25) of the large portion of the clip and the reference axis; - a second portion, called the large portion, defined between two edges (41, 42) on either side of the reference axis such that, on either side of the reference axis, the distance between the edge (41, 42) of the large portion of the opening and the reference axis is greater than the distance between the edge (24, 25) of the large portion of the clip and the reference axis