An attachment system to attach two parts to one another. The system includes a first part having a resiliently deformable hook and a second part includes a housing. The hook configured to be engaged in the housing so as to co-operate therewith by a reversible snap-fitting to mechanically bond the first and second parts together. The attachment system further includes a locking element which can be moved between a locking position, in which it opposes any deformation of the hook that would allow the hook to leave the housing, and a release position, in which it enables a deformation of the hook to allow the hook to leave the housing.