A federal appeals court has ruled that the former Harvard University classmates of Facebook founder Mark Zuckerberg can't undo their settlement over the social networking site.

The 9th U.S. Circuit Court of Appeals said Monday that Tyler and Cameron Winklevoss were savvy enough to understand what they were agreeing to when they signed the agreement in 2008. The deal called for a $20 million cash payment and a partial ownership of Facebook.

The twins had alleged they were misled about Facebook's value when they agreed to settle their lawsuit that claimed Zuckerberg stole their idea to launch Facebook.

The lawsuit was dramatized in the Oscar-nominated film, "The Social Network."

Monday's ruling upholds a lower court decision enforcing the settlement.