John Singleton's offer to shout racegoers in Rosehill's public bar areas if his horse wins the Golden Slipper is now locked in.

The Australian Turf Club has announced punters can toast another Singleton Golden Slipper victory if the Gai Waterhouse-trained Kiss and Make Up takes out Saturday's $3.5 million race.

"With John promising to shout the bar if their horse wins, all racegoers at Rosehill Gardens will be able to enjoy free beer and sparkling wine at the public bars, for the remainder of the afternoon," the ATC said in a statement.

The ATC will also dig into their pockets to shout members $20 worth of drinks no matter the outcome.

Singleton has shouted racegoers numerous times, and did so when Belle Du Jour won the 2000 Golden Slipper.

He also said he would extend his shout to the numerous pubs he owns around Sydney.