The Grammy-winning Chainsmokers are enduring a barrage of jokes on social media ever since their concert performance in Pittsburgh on Saturday night. The online teasing boils down to something like this: Next time, use spellcheck.

Currently on tour to promote their latest album, “Memories … Do Not Open,” the duo “mesmerized” the audience with an array of production effects throughout the concert, according a review in the Pittsburgh Post-Gazette, including “animated, comic book-style backdrops, an automated DJ table that raised and lowered, thick clouds of smoke, multiple storms of confetti, pyrotechnics” and several live skits.

But as the duo performed its encore to close the concert a huge sign came down that read “Thank You Pittsburg.”

The typo didn’t go unnoticed. Here’s some of the feedback on Twitter.