Kourtney and Khloe Kardashian will act as joint maids of honour for their sister Kim Kardashian.
The reality TV star will wed boyfriend Kris Humphries during the summer and according to Khloe, 26, both she and Kourtney, 32, will share the role on their sibling's big day.
When asked who will be maid of honour, Khloe told X17 "Both of us."
Younger half sisters Kendall and Kylie Jenner - from their mother Kris' second marriage to Bruce Jenner - are expected to be bridesmaids.
Kim - whose basketball star boyfriend Kris proposed last month with a 20.5 carat Lorraine Schwartz diamond ring - is reportedly eager to marry as soon as possible and the couple are planning a wedding shower in a month followed by the ceremony soon after.
A source said: "The wedding will happen within six to eight weeks. The wedding shower will take place about a month from now, They're doing things very, very quickly. It's being fast-tracked."
Friends of 30-year-old Kim have previously revealed she is hoping her wedding will rival that of Britain's Prince William and Princess Catherine, who married in Westminster Abbey In April.
A pal said: "Kim is planning the wedding of the century. She doesn't see why a Royal Wedding should get more attention that hers. She sees herself as a bigger celebrity than Kate Middleton."