MOCA Gala, Los Angeles, America - 14 May 2016
Credit: Andreas Branch/WWD/REX/Shutterstock

It's been 15 years since Vince Vaughn, Will Ferrell, and Owen Wilson attempted to snap out of their middle-aged funk by starting a fraternity in Old School. Wait, or was it Luke Wilson?

See, this is the problem when you have brothers who have often shared the screen and similar roles. Let's recap: Both Luke and Owen are Wes Anderson regulars, memorably appeared opposite Vaughn and Ferrell, starred in an emotional dog movie, and are either blonde or the love interest in Legally Blonde.

So in honor of Old School‘s 15th anniversary and to forever clear up this confusion, EW has created the crucial "Which Wilson was it?" quiz. Test your Wilskills below. <div class="apester-media" data-media-id="5a83526a1488a0000127e021" height="428"></div><script async src="//"></script>