They took a pizza our hearts.

Pizza Hut’s beloved pro-reading program, Book It! turns 40 this month — with over 70 million kids eagerly participating since 1984, the New York Times reported.

Well-known to Gen Xers and older Millennials — basically, anybody old enough to remember when books didn’t have to compete with social media — Book It! was founded by Arthur Gunther, then president of the chain, after the White House asked the business community to “get involved in education,” the outlet explained.

The premise was and remains pretty simple — read enough books to get a certificate from your teacher, then take the certificate to your nearest ‘Hut and exchange it for a free personal pie.

And between pizza parties, you had the program’s legendary swag to tide you over — including bookmarks and buttons bearing the Book It! logo.

“I remember getting a little Book It! bookmark, and feeling so excited to take that to the Pizza Hut and get that personal pan pizza,” Frank Torok, 37, told the Gray Lady. “It was almost like currency.”

As of this writing, over 1.5 billion free pizzas have been dished out to American kids.

“When you have millions of kids who refer to the program as a ‘core memory’ of their childhood and school experience, you have created something magical,” company president Carl Loredo told The Times.

President Ronald Reagan himself commended the program in 1985, calling it a “creative initiative.”

“I don’t think I would’ve read as much without the Book It! program,” Torok told a reporter. “It gamified it in a very analogue way.”

While Book It! still exists, the treasured buttons and the little star stickers you placed on them after finishing a book were reportedly phased out in the mid-aughts — in favor of a digital tallying system.

But, as with so much else from the 1980’s and 1990’s, nostalgia heads can easily snap one up on Ebay — for as little as $5.