Article L824-4 of the French Code governing the entry and residence of foreign nationals and the right of asylum
A foreign national assigned to residence pursuant to articles L. 731-1, L. 731-3, L. 731-4 or L. 731-5 shall be liable to three years’ imprisonment if he or she fails to return to the residence assigned to him or her within the prescribed time limit or leaves the residence without authorisation from the administrative authority.