Retail giant Walmart caused a stir on Monday, after a listing for plus-size Halloween outfits appeared on their website under the heading “Fat Girl Costumes.”

The retail chain quickly backtracked, issuing an apology before changing the heading to “Women’s Plus-Size Halloween Costumes.”

“This never should have been on our site. It is unacceptable, and we apologize,” a spokesperson for the company said. “We are working to remove it as soon as possible and ensure this never happens again.”

A Twitter user named Kristyn Washburn first brought the slipup to the public’s attention with this tweet, People reported:

The widespread outrage caused by the ill-advised labeling made “Fat Girl Costumes” a top trend on the micro-blogging site, with several other users expressing their indignation:

Jezebel, which first reported the story, speculated that it might have been an inside joke by the site’s developer that wasn’t corrected before going live.

[People]

Write to Rishi Iyengar at rishi.iyengar@timeasia.com.