Skiffle will run in the Oaks after being supplemented for the fillies' Classic at Epsom on Friday, 3 June.
The Charlie Appleby-trained three-year-old has been added to the field for the mile-and-a-half Group One contest at a cost of £30,000.
The move follows Skiffle's impressive win under jockey William Buick in the Listed Height Of Fashion Stakes at Goodwood.
Eleven horses now stand for the race on the first day of the Derby festival.
Appleby said on Saturday: "She did a routine piece of work this morning and we were very happy with her, so she will be supplemented for the Oaks.
"She's a nice filly, she's done nothing wrong and if we can run into a place I'll be delighted."
The Oaks' field is headed by 1000 Guineas winner Minding, favourite for the race which now has a prize fund of £475,000.
Minding, who was second in the Irish 1000 Guineas, was one of five fillies trained by Aidan O'Brien left in at the confirmation stage.
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