Cillian Murphy isn't the best dinner companion while he's working.

Matt Damon, who stars alongside the Irish actor in "Oppenheimer," recently labeled Murphy the "worst dinner companion imaginable." Although, the reason why had to do more with the "Peaky Blinders" star's work ethic rather than his personality.

"What he meant by that was when you're working on a film — when you're being the character — there's very little room in your head for anything else," "60 Minutes" host Scott Pelley told Murphy.

"I've always been like that, I think," Murphy replied with a laugh.

‘OPPENHEIMER' STAR CILLIAN MURPHY FELT ‘PRESSURE’ TAKING ON ROLE IN EPIC CHRISTOPHER NOLAN MOVIE

Matt Damon and Cillian Murphy at the Oppenheimer premiere

Cillian Murphy shared why Matt Damon labeled him the "worst dinner companion imaginable" in a new interview. (Getty Images)

"It's because, to me, you have the time on set, which is a short enough time. You have 10 hours, maybe. And then the other part, if you've got a significant part, you're having to keep your lines fresh."

"And then the other big thing for me is sleeping. I love sleeping and I need sleep."

Murphy clarified that he's enjoyed his dinners with the "Good Will Hunting" actor since the cast wrapped filming.

"I've had lots of lovely dinners with Matt Damon since the movie has finished, and we've been out promoting it and stuff," he said. "At the time, yeah, you just don't have the room … in your head and you want as much sleep as possible."

Matt Damon and Cillian Murphy share a laugh

Matt Damon and Cillian Murphy enjoy a laugh at the "Oppenheimer" premiere. (Getty Images)

LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWS

Murphy stars as the lead character in "Oppenheimer," a film following the rise and fall of J. Robert Oppenheimer. The physicist, along with a team of scientists, spent years developing the atomic bomb.

Damon, Emily Blunt, Robert Downey Jr., Florence Pugh and Josh Hartnett are among the star-studded cast.

"They're such brilliant, brilliant actors," Murphy told Fox News Digital. "There's a reason why they are movie stars, and they're… just also great people."

"I'd worked with Emily before on ‘Quiet Place 2’… we were very close. And I think that was smart casting by Chris to put us as husband and wife."

The Oppenheimer cast at the premiere

Cillian Murphy stars alongside Matt Damon, Florence Pugh, Emily Blunt, Robert Downey Jr. and more A-list stars in "Oppenheimer." (Getty Images)

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

"Oppenheimer" hit theaters July 21. The Christopher Nolan film has been nominated for 13 Academy Awards, including a nod to Murphy for best actor.

Blunt and Downey Jr. are also nominated for best supporting actress and actor respectively.

The 96th annual Academy Awards will take place March 10 at the Dolby Theater in Los Angeles. Movie fans can tune into the awards ceremony on ABC.

Cillian Murphy smirks subtly on the carpet in all black for 'Oppenheimer'

Cillian Murphy stars as J. Robert Oppenheimer in the Christopher Nolan film. (Samir Hussein/WireImage/Getty Images)

CLICK HERE TO GET THE FOX NEWS APP