Patenôtre left Marseille at the end of April 1884 with a modified version of the treaty drafted by the Quai d'Orsay for signature by the king of Annam.

[5] On 6 June 1884, the imperial Chinese seal - a symbol of the vassal status of Annam which had been given to Gia Long - was melted and the Patenôtre Treaty was signed.

[6] He then proceeded to Shanghai where he arrived on 1 July[7] to settle with China the difficulties which had arisen over the evacuation of the Chinese troops from Tongking.

The next year Patenôtre signed with Li Hongzhang a treaty of peace at Tientsin, by which the French protectorate in Annam and Tongking was recognized, and both parties agreed to remain within their own borders in the future.

[9] In December 1891, Patenôtre was presented his credentials in Washington, D.C. as the French Minister to the United States, succeeding Théodore Roustan.

[19] On 27 March 1894, Patenôtre was married to Eleanor Louise "Nellie" Elverson (1870–1953) at 2024 Walnut Street in Philadelphia, Pennsylvania, the home of her father.

[21][22] Together, they had two daughters and a son:[23] Patenôtre died on 26 December 1925 at Menton, a commune in the Provence-Alpes-Côte d'Azur region on the French Riviera, close to the Italian border.