Younger Dr. Who fans probably didn’t know who Peter Capaldi was when he was announced as the next Doctor; older fans probably thought he was inappropriate due to his florid language on The Thick of It, and everyone in-between thought it was a great decision.

Dr. Who Christmas specialThe Dr. Who Christmas special is set to excite on Christmas Day

But whatever your thoughts on the 55-year-old, Glasgow-born actor’s appointment, your beloved Doctor is set to face some changes, as his hearty sidekick Jenna Coleman explains in an interview with Digital Spy.

"[Capaldi is] going to be so different to Matt [Smith]," she explained. "It will be a different show next year. We have a bit of a gap before we start filming the new series, so I have time to get my head around it all. Me and Peter will get together before Christmas to start rehearsing and the scripts will start coming in."

Capaldi is set to make his debut as The Doctor properly in the upcoming Christmas special, entitled The Time of the Doctor – an episode the current Doctor Matt Smith has promised will be explosive.

“The Christmas special for me is a bitter sweet episode because I’m leaving, but Steven has written a brilliant, adventurous, funny episode and I’m really thrilled with it,” he said to The Mirror. “I think it’s good for the Doctor to go out with a bang, a crash and a wallop. I’m pleased it’s really funny and mad. I hope it’s going to be a belter.”

The Thick of It actor was always Showrunner Steven Moffat’s first choice to replace the charismatic Smith, even though the 30-year-old’s decision to exit the show came as a surprise. "He's a huge fan of Doctor Who, so we asked and he was incredibly excited to come and audition," said Moffat.

Doctor Who's The Time Of The Doctor will air at 7.30pm on BBC One on Christmas Day.