A fan favorite guest character is returning in "The Big Bang Theory" season 11. Bob Newhart is heading back to the top-rated comedy and reprising his Emmy-winning role as Professor Proton/Arthur Jeffries.

Bob Newhart will mark his appearance in the episode airing on Thursday, Nov. 2, at 8:30 p.m. on CBS. “The Big Bang Theory” showrunner Steve Holland earlier hinted about his return in an exclusive interview with Deadline.

"[Newhart is] possibly one of my favorite guest stars from the past," Holland said. "He is a comedy legend who has won an Emmy for the role."

Filming for the episode, however, won't begin until mid-October and it's still unclear of the professor's return has something to do with the impending wedding of Sheldon Cooper (Jim Parsons) to Amy Farrah Fowler (Mayim Bialik).

Newhart's 'Big Bang' Emmy

Bob Newhart, a sitcom legend with over five decades of experience in the business, nabbed his very first Emmy award for guest starring on "The Big Bang Theory" in 2013. As Professor Proton, the veteran played a former TV scientist who serves as a mentor to Sheldon.

His recognition would come 51 years after his first Emmy nomination, according to The Hollywood Reporter.

"In the previous cases where I lost it's because there was somebody better in the group," Bob Newhart told the publication. "It's the logical explanation of why I've never won," he said.

More challenges for Sheldon and the gang

Meanwhile, Sheldon Cooper might be taking a big step in his life with his upcoming wedding to Amy but it won't happen in the next few episodes.

Holland revealed that the writers still do not know if "The Big Bang Theory" season 11 will actually close with the wedding ceremony as the couple will experience a few more hitches along the way.

Sheldon's work, for instance, will also undergo major changes. He and the gang have been working on a secret government project for two seasons and yet viewers have not seen much progress in this storyline.

Howard (Simon Halberg) and Bernadette (Melissa Rauch) will also have to learn to deal with a second baby too soon after having Halley. The couple got the shock of their lives when they found out about the pregnancy in the premiere of “The Big Bang Theory” season 11.

These changes will also impact Leonard (Johnny Galecki), Penny (Kaley Cuoco) and Raj (Kunal Nayyar) as well.

Everyone will be figuring out what’s the next step in their lives and if they are heading in the right direction.

The Big Bang Theory” airs on Monday nights at 8:30 p.m. on CBS but the show will move to Thursdays for November sweeps. The network renewed the series for season 12.