Mark Hamill cannot touch his beard until the “Star Wars Episode 7” has finished production.

During an interview with BBC, Hamill revealed he was “contractually-obligated” to keep the facial hair. Hamill also admitted he wasn’t expect to reprise his role as Luke Skywalker almost 40 years since the release of the first “Star Wars” film.

“It was certainly unexpected,” Hamill said. “We had a beginning, a middle, and an end. I never thought we’d come back. I still can’t believe it’s happening. You go on to those sets that evoke so many memories, it’s just astonishing.”

“Star Wars Episode 7” won’t be making an appearance at San Diego Comic Con International this year, but Hamill is upset he won’t be able to make it to the convention.

"I'm a comic book nerd myself, so I miss all you guys. Hopefully, I'll be back next year,” Hamill told BBC.

Alleged plot spoilers for the “Star Wars” production recently leaked online. The production hasn’t commented on the spoilers, but Hamill has spoken out against spoilers in an interview with The Orlando Sentinel back in June.

"This is a whole different world," Hamill said, referring to production leaks. "The first one, no one cared. The second one there was a lot of interest, but it was before the Internet. ... I tell people we're not trying to annoy you or tease you or play some massive game. Basically what the goal is to keep the surprises for the movie instead of spoiling them on the Internet."

Hamill admitted his worst fear is if “Star Wars Episode 7” doesn’t live up to the hype it’s amassed since the announcement.

“Star Wars Episode 7” is slated to hit theaters on Dec. 18, 2015.