As more and more people marry more than once, prenuptial agreements have become an important estate planning tool.

Marriage is a tricky institution, enough so to feed a thriving business for therapists and prime-time sitcoms alike. Re-marriage can be even trickier, especially when it comes to your estate planning. If you are considering re-marriage, you may be well advised to also consider a prenuptial agreement. Though it may not seem the most romantic gesture, a prenuptial agreement is simply an honest disclosure of both parties’ assets and agreement as to their distribution should the union dissolve, or at the death of either spouse. Enter re-marriage without one at your own risk – or that of your estate. Without a prenuptial agreement, your new spouse could invalidate your existing estate plan.

For example, suppose you and your new spouse each have children from a previous marriage. You intend for your house to pass to your children, but without proper planning and a prenuptial agreement in place, your new spouse could inherit your house and then pass it on to her children when she dies. Disinheriting your own children probably was not your plan.

You’ll need to follow special protocol to ensure your prenuptial agreement is valid, to include that it must be in writing, signed without pressure on either party, both spouses must read and understand the agreement, disclosures must be complete and completely honest, and the agreement cannot be grossly unfair or contain illegal provisions (such as a modification to child support obligations).

If you are already re-married and did not sign a prenuptial agreement, it may not be too late for you and your spouse to resolve these issues with a post-nuptial agreement.