He played in PSG's 2–0 victory over Lyon on 1 August in the 2015 Trophée des Champions at the Stade Saputo in Montreal, replacing Edinson Cavani after 63 minutes. Six days later he made his Ligue 1 debut, replacing Lucas Moura for the final minute of a 1–0 win at Lille. On 16 August, he was given a first start, in a 2–0 win over Gazélec Ajaccio at the Parc des Princes. In all competitions, Augustin made 17 appearances across the season, scoring once in a 4–1 home win over Troyes four minutes after coming on for Edinson Cavani on 28 November.