Dermot O'Leary is stepping in to replace Sir Terry Wogan on this Friday's Children in Need after he pulled out for "health reasons".
It will be the first time Sir Terry will not have hosted it since its 1980 launch.
Sir Terry, 77, is having a procedure on his back and is understood to have withdrawn in line with doctors' advice.
The show is also due to be presented by Tess Daly, Rochelle Humes, Nick Grimshaw and Fearne Cotton.
It's a huge honour to be asked to step into Sir Terry's shoes tonight; he is one of my broadcasting heroes and has been a source of support for me down the years.
I'd like to add my best wishes to Sir Terry for a speedy recovery, and I hope I do him justice and do my small part to make the night a success and make as much money as we can for disadvantaged children across the country.
Many stars are expected to feature in the show including One Direction, actress Dame Helen Mirren, former Doctor Who star David Tennant, Sherlock actor Martin Freeman and singer Ellie Goulding.
We are so sorry that Terry won't be with us as we know how passionate he is about Children in Need.
But we wish him a very speedy recovery and know he'll be watching from home and enjoying the show.