'Pretty Little Liars' getting a spin-off starring Sasha Pieterse and Janel Parrish

— -- "Pretty Little Liars" is getting a spin-off.

Freeform has ordered a drama pilot called "Pretty Little Liars: The Perfectionists," the network announced Monday.

The spin-off, from "Pretty Little Liars" showrunner I. Marlene King, is based on another book series by "Pretty Little Liars" author Sara Shepard.

"At Freeform, we are committed to delivering shows that push boundaries and become a part of our viewers' lives. 'Pretty Little Liars' was a cultural phenomenon so it's no wonder fans wanted more," said Karey Burke, Freeform's executive VP of programming and development. "We can't wait to continue Marlene King's rich and revolutionary storytelling with a new crop of leading ladies from Beacon Heights who will hold just as many secrets and lies as Rosewood did."

The new series will star original cast members Sasha Pieterse and Janel Parrish. The two actresses will reprise their roles of Alison DiLaurentis and Mona Vanderwaal, respectively.

"The Perfectionists" is set in the fictional town of Beacon Heights, which seems perfect on the surface, but holds dark secrets. The residents’ quest for perfection leads to the town’s first murder.

"I can’t wait to introduce our fans -- and Sasha and Janel -- to a new world of thrills and chills in Beacon Heights,” King added in her own statement.

There is no word yet on when the new pilot will begin shooting. Pieterse is currently competing on the 25th season of "Dancing With the Stars."

"Pretty Little Liars" ended its seven-season run in June.