Zac Efron is celebrating his big day.

On Monday, the "17 Again" actor turned 34 and marked the occasion with an uplifting Instagram post.

For his post, the actor posed shirtless wearing only dark-colored swim trunks as he and a chocolate lab waded in the crystal clear waters of Thailand. The actor, showing off his muscular figure, also donned a smile from ear to ear.

"It’s my bday again?" Efron began in the caption. "I’m gettin old now- thanks for the bday wishes everyone I love you."

ZAC EFRON ADMITS HE NEVER WANTS TO GET IN 'BAYWATCH' SHAPE EVER AGAIN: 'IT'S JUST STUPID'

Zac Efron celebrated his birthday by sharing a shirtless photo taken in Thailand. (AP)

He said that he finds himself "amazingly lucky" to be on an "amazingly fun ride" with his fans and loved ones.

"This one feels very special as I get to spend it in Thailand, alongside the most talented and kind cast and crew, making a movie that I think will be awesome…" he added. "Couldn’t be a happier moment in my life. Love you all so much."

ZAC EFRON SPLITS FROM AUSTRALIAN GIRLFRIEND VANESSA VALLADARES: REPORT

The actor is in Thailand to shoot the Apple TV+ movie "The Greatest Beer Run Ever," co-starring Russell Crowe and Bill Murray.

Zac Efron is in Thailand filming ‘The Greatest Beer Run Ever.’ (Photo by Jordan Strauss/Invision/AP)

The movie follows Efron's John Donohue, a U.S. Marine Corps veteran who is convinced to sneak into Vietnam to wish his friends still in combat well in person.

Plenty of fans took to the comments of the actor's Instagram post to wish him a special day.

ZAC EFRON SPEAKS OUT AFTER REPORTEDLY CONTRACTING SERIOUS ILLNESS WHILE FILMING SERIES 'KILLING ZAC EFRON'

"HAPPY BIRTHDAY TROY BOLTON," one wrote, referring to the star's character in the "High School Musical" trilogy.

Efron said he expects ‘The Greatest Beer Run Ever,' co-starring Bill Murray and Russell Crowe, to be ‘awesome.’ (Photo by Brendon Thorne/Getty Images for Paramount Pictures)

"Happy birthday love of my life," gushed another.

CLICK HERE TO GET THE FOX NEWS APP

"Omg!!!" a third wrote. "ZAC HAPPY BIRTHDAY."

Added a fourth: "HAPPY BIRTHDAY MY LOVE."

CLICK HERE TO SIGN UP FOR OUR ENTERTAINMENT NEWSLETTER