Fans hoping to score second-hand tickets to either of Louis C.K.’s sold-out Vancouver shows might want to think twice, the comedian warns.

The famed funnyman’s two performances at the University of British Columbia in December are his only scheduled stops in Canada, and tickets to both were gone within hours of going on sale Tuesday.

But in a message to fans, C.K. cautioned anyone who missed out against resorting to reseller websites.

“We take great efforts and have many methods of finding out what inventory is being sold on ‘broker’ sites like Stubhub and Vivid Seats and immediately invalidating those tickets,” the comedian said in a message on his website.

“If the ticket becomes invalidated, we are not responsible, and unfortunately the consumer could lose money and not get into the show.”

C.K. said he can’t confirm which seats will be invalidated, but there is “a legitimate chance that any and all of them can be.”

Tickets to C.K.’s Vancouver shows ranged from $25 to $65 on Ticketmaster – relatively affordable for one of the most popular comedians touring.

The two-time Emmy winner has been vocal about his efforts to prevent fans from getting gouged in the past, either by ticket company fees or scalpers.

During his tour in 2012, C.K. offered tickets exclusively through his website to avoid the usual charges. He also announced he was taking measures to prevent resellers from turning a profit.

“If you try to sell the ticket anywhere for anything above the original price, we have the right to cancel your ticket (and refund your money),” he said while announcing the tour.

“There are some other rules you may find annoying but they are meant to prevent someone who has no intention of seeing the show from buying the ticket and just flipping it for twice the price from a thousand miles away.”

As of Wednesday morning, there were no tickets to his upcoming Vancouver shows for sale on StubHub or Vivid Seats, and the vast majority of Craigslist posts were from people hoping to buy, not sell.