Steven Moffat told how the makers of the popular BBC programme were delighted with the actor using his Glaswegian twang for the role.
Moffat, himself a Scot, revealed how the Time Lord’s “doomed” dialogue sounds even more convincing when spoken in a Scottish brogue.
The Thick of It star is currently filming his first series as the Doctor in Cardiff after replacing Matt Smith. Two other Scots, David Tennant and Sylvester McCoy, have taken on the role but Capaldi, 55, is the first to play it in his native tongue.
Moffat, the show’s lead writer, told how the cast and crew were thrilled with the scenes Capaldi has shot so far.
Asked what viewers could expect from the new Doctor, Moffat, originally from Paisley, Renfrewshire, said: “Scottishness. I think that’s the main thing.
“I mean watching him, and I just watched episode two actually, you don’t go around thinking this is an older bloke as The Doctor, particularly.
“You just think my God, he’s Scottish. And doomed dialogue doesn’t half sound great in Scottish. You say the world’s about to end in a Scottish accent, and you really believe it.”
When Tennant joined the hit show as the tenth Doctor in 2005, he said: “I’d love to be the first Time Lord to wear a kilt.”
But writer Russell T Davies said he did not want the Doctor’s voice “touring the regions”.
The BBC has said the decision for Capaldi to have a Scottish accent was a “creative decision”.
Filming for series eight of the show began in January.