Giro d'Italia organisers have removed the race's highest climb and shortened Friday's 207-kilometre 13th stage to 199km due to snow and the risk of avalanches.
The 2,469m ascent up the Great St Bernard Pass was positioned as this year's Cima Coppi, the highest climb of the race.
Organisers said on Tuesday cyclists will instead ride through the tunnel during the route from Borgofranco d'Ivrea to Crans-Montana.
"Given the exceptional snowfall, and in the light of the avalanche danger, it is announced that the race will not pass over the Great St. Bernard Pass, but through the tunnel," organisers said in a statement.
"As a result of this change, the stage will have a length of 199 kilometres... The meeting and start time remain unchanged."
The 2,304m Tre Cime di Lavaredo on stage 19 will now be the highest climb of this year's edition.
