On 21 January 2015, Aaquist signed with FC Helsingør on a free transfer.Helsingør snupper frigivet FCK'er, bold.dk, 21 January 2015 He signed a contract until the summer 2015, and later extended his contract after playing 14 league games for the club in his first 6 months.Helsingør forlænger med spillelysten back, bold.dk, 11 June 2016 He got his debut for FC Helsingør on 26 July 2015. Aaquist started on the bench, but replaced Jonas Hebo Rasmussen in the 60th minute in a 0-3 defeat against FC Roskilde in the Danish 1st Division.
