As we say goodbye to Peter Capaldi on Doctor Who this week, Mark Gatiss has shared a nice behind-the-scenes moment with the Twelfth Doctor.

Gatiss – who starred in Christmas special ‘Twice Upon a Time’ and has written numerous episodes – snapped Capaldi on his last day wearing a piece of Doctor Who history.

“Thanks for all your kind words about ‘Twice Upon a Time’,” he captioned the picture of the star in a purple jacket. “Here’s Peter on his last day, wearing Jon Pertwee’s jacket from ‘Planet of the Daleks’!”

Thanks for all your kind words about 'Twice Upon a Time'. Here's Peter on his last day, wearing Jon Pertwee's jacket from 'Planet of the Daleks'! pic.twitter.com/asBfUsRY6U

— Mark Gatiss 💙 (@Markgatiss) December 28, 2017

Pertwee played the Third Doctor between 1970 and 1974, and sported one of his most iconic looks in the 1973 serial ‘Planet of the Daleks’.

Capaldi has also been giving out emotional advice in the wake of his exit, notably after one young fan expressed concern over his regeneration.

“Even though [regeneration] can be a little icky (like a really bad flu), it has always, always turned out good for Doctor Who,” Peter told young David in his note. “The New Doctor always becomes your favourite and the one that goes… Well, he never really goes.

“He is always there, somewhere in time and space, and if you think about him hard enough, you’ll see him and he’ll see you. It’s like The Doctor says, ‘Everything ends and it’s always sad. But everything begins again and that’s always happy.’ Be happy.”

As Twelve left the universe, we got the chance to say hello to the Thirteenth Doctor, played by Jodie Whittaker.

Doctor Who will continue with its 11th series in 2018 on BBC One in the UK and BBC America in the US.