Nico Hulkenberg has been ruled out of defending his victory in the 24 Hours of Le Mans, due to a change in the Formula One schedule, released Wednesday.

The European Grand Prix in Baku, originally scheduled for July 17, has been moved forward one month to June 19, which now falls on the same weekend as the French endurance classic.

A statement released by the FIA World Motor Sport Council, however, said the Baku race start will be scheduled to avoid conflict with the conclusion of Le Mans.

Hulkenberg, who recently signed a multi-year contract extension with Force India, had been poised to return to Le Mans next year alongside his winning co-drivers Earl Bamber and Nick Tandy.

The clash could open the opportunity for Juan Pablo Montoya, who is set to test Porsche’s 919 Hybrid later this year, to potentially replace the German in the lineup, should Porsche again commit to a three-car entry for the race.

INDYCAR has yet to release its 2016 schedule but it’s believed there will not be a clash, which would enable the Colombian to take part in the race.