Jennifer Aniston will always be there to celebrate with her friends!

Paying tribute to her fellow Friends alum, Courteney Cox, Aniston took to Instagram to wish her a happy 59th birthday on Thursday.

"I'd like to take a moment and wish my dearest CC the happiest of birthdays," Aniston, 54, captioned a compilation of throwback images and videos. "If you've been lucky enough to know her, you know how incredible she is."

Aniston added, "The biggest heart and most generous of humans. I love you, Cox-N-Hammer! Happy Birthday ❤️🥳🎈"

The carousel featured moments of the duo throughout the years, including an old shot of the friends exchanging a kiss and snippets of them laughing while filming their hit sitcom Friends.

This isn't the first time Aniston has publicly shown love to her longtime friend and costar. 

Back in February, The Morning Show actress honored Cox in a joint speech with Lisa Kudrow as she received her star on the Hollywood Walk of Fame. 

"We're very honored to be here today to speak on your behalf as your co-workers, your friends, and your family, your sisters," Aniston said. "And that's happened since we've known you for a very long time."

She gushed, "To be friends with Courteney is to be family with Courteney. She is responsible for all of that. From the beginning of when we met her, she was immediately inclusive, warm, loving, interested in everything about you.

"As fans we want to thank you for making us laugh," Aniston concluded. "Watching you on screen and just in life in general, you're one of the funniest human beings on the planet Earth. Nothing makes me happier than a Courteney joke and always making us smile and thank you for enriching our lives with your work. We are so proud of you, we love you, you're sisters from another mister and we love you."

In her own speech, Cox also thanked Aniston and Kudrow for supporting her throughout the years. 

"I love you all so much and it's so nice that you came out and showed up for me in public the way you do so often in private," she shared.

Friends ran for 10 seasons on NBC from 1994 to 2004. Aniston (Rachel Green), Cox (Monica Geller),  Kudrow (Phoebe Buffay), Matt LeBlanc (Joey Tribbiani), Matthew Perry (Chandler Bing) and David Schwimmer (Ross Geller) all got back together for the HBO Max special, Friends: The Reunion, in 2021.

During the special, which premiered in May of that year, the stars revealed a number of behind-the-scenes tidbits from their time on the show. They also reminisced about being a part of the hit series.

"It was an incredible time," Cox told her costars during the unscripted special. "Everything came together. We became best friends through just the chemistry, the whole thing. It was life-changing and it forever will be - not just for us, but for people who watch it, and that's such a great feeling to carry forever. I'm really thankful, and I love you guys so much."