(CNN) -- Tour de France organizers have been forced to make changes to the route of this year's race because of fears of falling rocks.
Race organizers feared that the safety of cyclists and spectactors would be at risk.
Officials were worried about threats to the safety of riders during the planned 4km (2.5-mile) climb up the Col de Larche during the 15th stage, according to the race's official Web site.
They have now decided to switch the leg, which was due to start at Digne-les-Bains on July 20, to leave from Embrun.
Instead of facing the Col de Larche, the pack will have to face the climb up the Col d'Agnel, whose altitude is 2744 meters (9,000 feet).
The stage will be 30km shorter than planned, taking off from Embrun and heading the 185km to Prato Nevoso.
"The organizers of the Tour de France have decided, after speaking to the local authorities and following the recommendations of the State departments, to modify the itinerary in order to guarantee the security of the riders, the spectators and the followers of the Tour," a statement said.
"The risk of rock falls on about 4km of the course has been known for several months and all the parties concerned have been trying to find a solution.
"Unfortunately, three months before the start of the Tour, the works considered could not guarantee the necessary security for the passage of the race, and based on the time necessary for the study of a new course, wisdom commanded to change the itinerary."
The race will begin in Brittany on July 5 and conclude on the Champs-Elysees on July 27, with 20 teams being invited to race. There will be 21 stages: 10 on the flat; nine at varying mountain altitudes; and two individual time-trials. E-mail to a friend