After spending weeks due to his international commitment with Belgium U23, Haroun made his Germinal Beerschot debut, where he started the whole game, in a 1–0 loss against K.V.C. Westerlo on 30 August 2008. In a follow–up match, Haroun scored twice, in a 3–0 win against K.S.V. Roeselare. Since making his debut, he quickly became a first team regular, playing in the midfield position. Haroun also stated that he's enjoying football more at Germinal Beerschot than Genk. It wasn't until on 9 November 2008 when he scored his second goal of the season, in a 3–1 loss against Standard Liège. Haroun then scored two goals in two matches between 18 January 2009 and 24 January 2009 against Genk and FCV Dender EH. After missing one match due to injury, he scored twice on his return from the starting line–up, in a 3–0 win against K.V. Kortrijk. Haroun then scored his eighth goal of the season, in a 3–1 win against K.V. Mechelen on 8 May 2009. At the end of the 2008–09 season, he went on to make thirty–two appearances and scoring eight times in all competitions. For his performance, Haroun was placed second behind Silvio Proto.