The player's contract with the Bundesliga title holders will include a buy-out clause that could see him leave for a fixed fee in three years time
Last week, Express claimed the Germany international's contract includes a provision that will require Dortmund to sell the player in 2014, should an offer of €30 million be made for his services.
Now, Bild have reported that the value of the exit clause is instead €35m, and it will take effect in 2015.
Reus, currently at Borussia Monchengladbach, has yet to officially put pen to paper on a contract, but has agreed to a five-year deal until 2017, effective this summer.
However, the finer details of his move, such as a potential buy-out clause, may be negotiated until the final contract is signed.
The 22-year-old has been in superb form this season, scoring a total of 13 goals in 18 appearances in all competitions.