Though some people still think of creating a prenuptial agreement before marriage as bad luck, many people find the document provides peace of mind, in case their early marital bliss ever fades away. A prenup can ensure that valuable assets like a small business or real estate stays with you, without having to buy out your former spouse or losing the assets entirely.

Spouses-to-be can use a prenuptial agreement to decide how to divide up most of their assets if they ever divorce. This could mean avoiding a big headache down the road. However, in most states you cannot pre-plan your entire divorce, so it makes sense to find out now what things cannot be included in a prenup.

Two big issues that most states do not allow you to decide in your prenuptial agreement are child support and child custody. Courts consider these issues to be matters of public policy that must be decided in the best interests of the child.

In addition, most states strictly limit the ability of either spouse to waive their right to alimony, and a few outright prohibit such clauses. And prenups generally cannot be used to control the spouses’ personal behavior. Provisions about where the couple is to spend the holidays and which spouse is responsible for doing the laundry are not enforceable in court. A judge who finds this type of language in a prenup is liable to throw out the entire document.

To ensure that your prenuptial agreement is clear, valid and accurately reflects you and your spouse’s wishes, it is a good idea to have an attorney review it. And if you do end up getting divorced later, an attorney can help you challenge the prenup, if necessary, or defend it in court.