The Frenchman departed Glasgow for Ligue 1 on transfer deadline day last summer in a £19.7 million move, after two successful seasons with the Scottish champions.
Dembele has scored seven goals in 18 appearances since returning to his home country, including a header as Lyon became the first team to defeat Paris Saint-Germain in the league with a 2-1 victory on Sunday.
Speaking about his move, the striker revealed that the Ligue 1 side impressed him with their eagerness to land him.
“It’s a club with a great history, there was a project that interested me,” he told Telefoot.
“And I felt the determination of the leaders to bring me to the club, and that was decisive in my choice to come to Lyon. [For me] it was Lyon or I [would have] stayed at Celtic.”
Dembele was also questioned about rumoured interest from Marseille in the past.
“Marseille … Marseille, it’s complicated, it’s complicated. The club is not too stable I’ll say,” he said.
“Well, I don't really want to talk about Marseille. I’m Lyonnais and I’m happy to be at Lyon, that’s most important.”
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