A glitch with Amazon (AMZN) UK caused items to be listed for a penny on Friday.

The glitch behind the Amazon UK price drops wasn’t actually Amazon’s fault. The problem came from Repricer Express, which is a program that automatically adjusts items’ prices.  The program is used by third-party sellers to help maintain their online stores, reports Engadget.

Shoppers were quick to take advantage of the glitch that lowered Amazon UK prices. However, many sellers are working with the online retailer to have the orders cancelled, Engadget notes.

Third-party sellers are frantically trying to undo the damage that was caused by the Amazon UK glitch. Some are worried that if all the orders aren’t cancelled then they could go out of business. These are mostly small, family-owned business that use the website, reports Business Insider.

More From InvestorPlace