The couple, who confirmed their engagement earlier this month, are said to be planning a double celebration as their wedding will coincide with Pitt's parents Bill and Jane's golden wedding anniversary.
Up to 300 guests, including George Clooney, Matt Damon, Johnny Depp and Tom Cruise, are expected to attend the ceremony at the pair's £35m French château.
"They thought their kids would love the idea of seeing mom and dad get hitched followed by a big bash for them as well as 'Meemaw and Grandpa' as they call Brad's folks," a source told the Daily Star Sunday.
"[Jolie] came up with the idea of making it a real family celebration by merging Bill and Jane's special day with theirs.
"Brad's family mean a lot to Angelina, especially since she lost her own mum Marcheline to ovarian cancer more than five years ago and spent years refusing to talk to her father.
"The kids have been asking when they're going to get married for years. Now they are pretty much the main reason Brad and Angelina are tying the knot."
Maddox, ten, Pax, eight, Zahara, seven, Shiloh, six, and twins Knox and Vivienne, three, will be heavily involved in the wedding ceremony.
Jolie's dad Jon Voight recently said that he is "very happy" for his daughter.
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