People shocked after realizing Bernard from The Santa Clause was in Oppenheimer

Bernard the Elf from The Santa Clause appears in Oppenheimer and it's leaving people shook.

There's nothing like an actor who was a child in one of your favorite Christmas movies cropping up in a recent release to make you feel even more ancient than your aching back, sore neck and eye-bags already make you seem.

Despite Oppenheimer being released into cinemas earlier this year in July, viewers are still reeling after realising David Krumholtz - who played Bernard the Ef in 1994 release The Santa Clause - features in the movie.

Prepare to be 'gobsmacked':

Krumholtz appeared in The Santa Clause at the age of 16-years-old, with his character of Bernard the Elf being a firm favorite of viewers - so much so, the actor told TIME the internet reaction was 'so violent' they had to make sure he return for the sequel.

In the interview, the 10 Things I Hate About You star also noted The Santa Clause is the film for which he's 'recognized for most'.

However, the 45-year-old can now add another movie to his most-recognized list - with Oppenheimer viewers having flooded to social media to identify him as playing the role of physicist Isidor Isaac Rabi - friend of J. Robert Oppenheimer (Cillian Murphy).

Buena Vista Pictures Distribution

A TikToker named Hannah Louise - who goes by the username @hdzialowski - took to the platform earlier this year to share her surprise once she realised that Krumholtz makes an appearance in Oppenheimer.

The caption of her post reads: "From Santa's helper to American physicist who won the Nobel Prize in physics in 1944."

In another video - clearly still not over the realisation - she adds: "The way I could not concentrate on Oppenheimer when I realized... Bernard has made a career change and I'm here for it."

And other TikTokers have flocked to the post in equal shock. One user wrote: "Omg this is where I recognise him from."

"I FVCKING KNEW IT," another added.

And a third commented: "I'm in shock."

Universal Pictures

Fans of the actor have similarly taken to X - formerly known as Twitter - to weigh in on the spot.

A user wrote: "Oh shoot I didn't know that!"

"It's a hell of a performance too," a second noted.

And a third commented: "Yeah haha I noticed that in the theater! I mentioned it to a few others after it ended and we were all gobsmacked."

However, a fourth said they were 'shocked how many people didn’t know this', adding: "Dude’s a national treasure and grew up in the same building in Queens as my gf."