The comedian will reunite once again with Ricky Gervais and Stephen Merchant for the Warwick Davis-led sitcom next year.
He explained that one episode will centre around himself, Shaun Williamson and Keith Chegwin.
Speaking on the Peacock And Gamble Podcast, Dennis said: "I'm just going to tell you guys something we can now talk about, which I'm really excited about, is that myself, Keith Chegwin and Shaun Williamson will be working for Ricky and Stephen again next year.
"You know Life's Too Short, the series? They are doing a special next year and they have written it around us. We are going to film in next February."
The one-hour special is expected to air in the spring of 2013.
BBC Two controller Janice Hadlow recently defended the ratings, critical response and controversy of Life's Too Short.
Shaun Williamson has also spoken of his hopes of filming a spinoff featuring his 'character' from Extras and Life's Too Short.
Watch a clip from Life's Too Short below: