Paul Giamatti will be bringing his thespian skills to “Downton Abbey” next season, but don’t worry about his accent. The “Sideways” actor will be joining the cast as another American character; Cora’s brother Harold, uncle to Lady Mary and Lady Edith.

According to TVLine,  Giamatti’s character is described as something of a “maverick” and “playboy.” In an interview, Carnival Films Managing Director Gareth Neame said that Harold was “free-spirited,” and vowed that both he and his mother, played by Shirley MacLaine, would “upset the Grantham’s apple cart” in the season finale.

“Downton Abbey” won’t be Giamatti’s first trip to the small screen. He’s appeared on “30 Rock” and gained both an Emmy and a Golden Globe award for his titular role in the 2008 TV miniseries “John Adams.”

Other confirmed new additions to the cast include Tom Cullen (of “Weekend” and “Black Mirror”) as Lord Gillingham, a friend of the Crawley family; Nigel Harman as a new valet, Green; and Dame Harriet Walter as Lady Shackleton, a friend of the Dowager countess, the Huffington Post reported. Other newcomers are Joanna David, Julian Ovenden, Dame Kiri Te Kanawa and Gary Carr, who will play the first black character on the series.

The much buzzed-about show has also faced rumors that it would be hosting cameos from Gwyneth Paltrow and the Rolling Stones, although neither of those stories were ever confirmed, according to Gossip Cop.

Series creator Julian Fellowes, who also wrote “Gosford Park,” described the death of one of the show’s chief characters last season as “testing,” and for that reason, has said that the next season will begin six months later. “We knew Jessica [Brown Findlay] was leaving from quite a long time before,” Fellowes said. “And so we completely decided calmly to kill her off in the fifth episode, so that would give people three episodes to recover, and then we’d have the Christmas special and everyone could move forward.”

“‘So we had a whole episode of her dying. But having done that, when the news came through that Dan [Stevens] was also leaving we couldn’t very well do it again, so that was a bit testing,” he added.

Season 5 of “Downton Abbey” will air on PBS on Sunday, Jan. 5.

View an interview with the cast for the Hollywood Reporter below.