The WBC will award the Elizabethan Belt, created in honor of the late Queen Elizabeth II, to the winner of next Saturday's matchup between Savannah Marshall and Claressa Shields.
"I think the belt is brilliant, The WBC always pulls out the stops," Marshall said in a statement. "It's one of a kind and it's staying in the UK. How can she walk away with that? That can't leave this country, it wouldn't be right."
Marshall and Shields are set to fight at London's O2 Arena, marking the first major prizefight in the United Kingdom since the Queen's death in September.
The main event will be part of an all-female card, which will also include a fight between Mikaela Mayer and Alycia Baumgardner to unify the junior lightweight championship.
The Elizabethan Belt features the flags of Marshall (United Kingdom) and Shields (United States) while honoring the Queen with her name, crown and lifespan etched across the purple belt.