After his return from the campaign of Russia (1812), he was promoted to Chef de Bataillon and chief engineer in the corps of military engineers. Audoy campaigned in Saxony (1813) where he fortified Dresden, then participated in January 1814 in the defense of Metz. On 9 November 1814, he was elevated to the rank of Officer of the Legion of Honor. On 18 June 1815, he participated in the Battle of Waterloo, where he was wounded.