Kim Kardashian and new fiance Kanye West are reportedly committed to making their relationship last but apparently aren't certain enough it will to go without a prenuptial agreement.

The Keeping Up with the Kardashians star and West will be signing a prenup to keep their assets separate before they get married, TMZ reported.

According to sources close to the couple, Kardashian and the rapper have reportedly opted to get a prenup not because they're worried about eventually divorcing but because they believe it's the smart business decision given both parties are very wealthy.

Kardashian, allegedly worth $40 million, and West, allegedly worth $90 million, will share one joint account, however, for all their living expenses.

According to TMZ, part of the reason Kardashian wants a prenup is because her late father, attorney Robert Kardashian, stressed to his daughter the importance of drawing monetary contracts before marriage when he was alive.

West proposed to Kardashian in dramatic fashion on Monday at AT&T Park in San Francisco and she accepted. They have a four-month-old daughter together named North "Nori" West, who was born on June 15.

This will be the first marriage for West and the third for Kardashian, who had divorced music producer Damon Thomas in 2004 and NBA basketball player Kris Humphries in 2011.