Claudia Gadelha and Joanna Jedrzejczyk will meet this December in a possible No. 1 contender match for the vacant UFC female strawweight title at UFC on FOX 13.

Officials added the bout to the December 13 card from Phoenix’s U.S. Airways Center on Friday. The main event features Junior dos Santos vs. Stipe Miocic.

Gadelha (12-0) is widely-considered one of the top 115-pound females in the world, but the constant weight cuts The Ultimate Fighter 20 would have required kept her from appearing on the show. She earned a victory over Tina Lahdemaki earlier this year.

Jedrzejczyk (7-0) also won her debut when she topped Juliana de Lima Carneiro in July. The 27-year-old has stopped three of her opponents.

Below is the current lineup:

Heavyweight: Junior dos Santos vs. Stipe Miocic

Lightweight: Nate Diaz vs. Rafael dos Anjos

Heavyweight: Stefan Struve vs. Alistair Overeem

Lightweight: Jamie Varner vs. Drew Dober

Middleweight: Derek Brunson vs. Ed Herman

Lightweight: Joe Ellenberger vs. Bryan Barberena

Heavyweight: Gabriel Gonzaga vs. Matt Mitrione

Welterweight: Ben Saunders vs. Joe Riggs

Flyweight: Jussier Formiga vs. John Moraga

Bantamweight: Ian Entwistle vs. Anthony Birchak

Lightweight: David Michaud vs. Garett Whiteley

Female Strawweight: Claudia Gadelha vs. Joanna Jedrzejczyk