Aniston, 50, shared a throwback pic of her and Perry, 50, to celebrate his arrival to the social media site. Next to it, she wrote, "I'm shocked Matty is the last to join Instagram, considering he was a uh ... umm ...oh crap. Oh! A computer processing TRANSPONSTER."
"Friends" fans knew Aniston was referring to the season four episode when Rachel (Aniston) and Monica (Courteney Cox) lose their swanky apartment to Chandler (Perry) and Joey (Matt LeBlanc) during a trivia game made up of questions about each other.
During the game's lightning round, Rachel and Monica blunder the question, "What is Chandler Bing's job?"
Both women panic — it was a recurring joke on the show that Chandler's pals never knew what he did for a living — before Rachel fudges a response about Chandler being a computer "transponster."
"That's not even a word!" Monica cries.
Swipe right on Aniston's post to see a clip of the memorable scene.
Perry's account, @mattyperry4, had 2.8 million followers as of Friday afternoon despite the fact that he hasn't posted a single pic yet. His profile photo features a black-and-white photo of the actor asleep, holding what looks like a yellow smiley-face balloon.
Aniston's post comes a day after Lisa Kudrow, 56, used her own "Friends" reference to welcome Perry to the site.
"Finally!!! Yay!! Can’t believe my eyes MY EYES Welcome to Instagram @mattyperry4 #friendsforlife," she captioned her own throwback pic with Perry.
Courteney Cox took the comments, writing, "Yes Matty!!!" while Aniston joked, "Yay Matty! Could you TAKE any longer?"
Guinness World Records announced the following day that the "Morning Show" star had racked up 1 million followers faster than any other Instagram user — hitting the milestone in only 5 hours and 16 minutes.
We guess this is what people mean by "Friends" forever!