The 44-year-old Marley & Me actress, announced her engagement to Zoolander 2 actor, Justin Theroux, in August 2012.
Speaking to Life & Style, Aniston admitted that she's yet to pick out a dress for her big day, saying: "I don't have a dress… I like to be very spontaneous.
The Horrible Bosses actress also insisted that she is not looking forward to actually planning the wedding, adding: "[It's] something that will probably come together at the last minute. [Too much planning] might make me crazy!"
The former Friends star was previously married to Brad Pitt, who reportedly called to congratulate the actress on her new engagement last year.