It's been 34 years since they first co-starred in the original Terminator movie.

And now Arnold Schwarzenegger and Linda Hamilton have been reunited on the set of Terminator 6.

The action star, 71, paid tribute to Linda on her 62nd birthday on Wednesday by sharing a photo of them on his Instagram .

Arnold posted a new photo of them together along with a throwback shot taken in 1991 when they were filming Terminator 2: Judgment Day.

(Image: Orion Pictures)

In the new shot, Arnie is seen covered in stage make-up to illustrate cuts all over his face.

He captioned it: "Happy birthday to my dear friend Linda Hamilton. One of my favourite co-stars, a true badass, and a wonderful human being. I'm pumped to be back together again."

Filming on Terminator 6 started in Spain in June, with Arnold starting his scenes in Hungary in July.

(Image: Paramount Pictures)

Former California Governor Arnie confirmed he was coming back as T-800 in summer 2017, with producer James Cameron announcing Linda would be reprising her role as Sarah Connor a few months later.

Sarah was originally killed off in the third movie Terminator Salvation in 2009, but Cameron confirmed the sixth film would be a direct sequel to Judgment Day and would disregard the subsequent films as alternative timelines.

The reboot, which is due for release in November 2019, also stars Mackenzie Davis, Diego Boneta, Gabriel Luna and Natalia Reyes.

Jude Collie will serve as the body double for a young John Connor, with Edward Furlong's 1991 facial likeness projected on using CGI.