The star of I Claudius and Brother Cadfael won’t have any lines, however. In fact, if you’re not paying attention you might miss him altogether.
Jacobi will appear in the background as a regular of the Rovers Return pub. His walk-on part was filmed last week when he visited the set in Manchester.
In a 2007 interview, he admitted that he’d always wanted to be in the soap opera, and had once gotten former Coronation Street star Bradley Walsh drunk in the hope of securing a part.
Cliff Richards's role, which was back in 1997, was similarly brief. He appeared with his back to the camera but his jumper, with the words "rock and roll" written across it, gave him away.
A spokesman for the show said, "We have tried for years to try and sort out a role in the show for Sir Derek but we have never quite managed it.
"We are as big a fan of his work as he is of ours. He is an Equity member, so there was no problem getting him on set.
"It is highly unlikely viewers would spot him but we hope it made his day."