The Project Runway contestants will seek inspiration from a very famous store for young girls on Thursday night’s episode.

Heidi Klum Wears Sean Kelly's Blue Dress To Creative Emmy Awards 

The designers will visit American Girl and subsequently create age-appropriate styles for young models.

“The @American_Girl girls are taking over the runway! Watch @ProjectRunway tonight on @lifetimetv! #ProjectRunway,” judge Heidi Klum tweeted on Thursday morning.

Heidi Klum Wears Zac Posen's Sleek Design To Emmy Awards 

Klum will critique the looks along with her fellow panel – Nina Garcia and Zac Posen – as well as Mad Men actress Elisabeth Moss, who will appear as the celebrity guest judge.

Moss, 32, previously was a guest judge on the show’s spinoff, Project Runway All Stars, last year. The actress spoke about the experience and revealed it was difficult to assess the contestants.

“When you have the designers right in front of you, most of whom look exhausted and stressed, it's terribly hard to be critical. Also, when you see the dresses in person you realize how insane it is that they have even constructed anything of that caliber in 24 hours or however long they have been given. I couldn't make a sheet to put over your body! I wouldn't even be able to make the hole for your head!” she told Marie Claire.

Project Runway airs Thursdays at 9 p.m. EST on Lifetime. The season finale airs on Oct. 23.