Chicago sports fans — especially Cubs fans — need to be on the lookout for counterfeit memorabilia ahead of the holiday season, the FBI warns.

“Following the great season the Chicago Cubs just had, counterfeiters may see this time as a good opportunity to take advantage of the fans’ excitement and distribute questionable items to the public,” Special Agent Brian Brusokas said in a statement.

“These items can include everything from autographs to game-used items such as jerseys, bats, balls and caps. We can also see a flood of unlicensed T-shirts and other items commemorating this special year,” said Brusokas, a member of the FBI’s Art Crimes team that investigates fraud regarding collectibles.

Some tips for shoppers:

• Before buying any limited-edition items such photos, card sets or display items, know the edition size. Brusokas said some limited-edition memorabilia is only limited by the amount of consumer interest.

• Buyers of game-used items like jerseys should know what a genuine on-field Cubs jersey looks like, and pay close attention to details such as the stitching patterns used to affix nameplates and patches.

• For autographed baseballs, buyers should try to compare the signature on the ball with known signatures of that player. And if the signature has been authenticated, check the qualifications of the authenticator.

• Know the seller and what their refund policy is.

• Remember, if an item seems too good to be true, it probably is.