BENTONVILLE, Ark. — Walmart has changed its Savings Catcher price comparison tool so that deals offered by drug stores are no longer matched.

The Savings Catcher tool, which is available on the Walmart smartphone app and on the retailer’s website, promises to make it easy for shoppers to compare Walmart’s prices with those offered by other retailers.

Shoppers simply scan their Walmart receipt with their smartphone (or enter the receipt number on Walmart’s website), and the tool will automatically compare the prices on the receipt with products featured in the print and digital advertisements published by other local retailers. If another retailer is found to have a lower price on the same item, the customer gets the difference back on a Walmart eGift card.

The idea is to allow Walmart customers to be confident they are getting the lowest prices while freeing them from the need to read through the circulars or online offers of competing retailers.

But a change made to the program last month means that offers made in drug store circulars are no longer included in the price comparisons.

“We are limiting our comparisons to offers of other mass market retailers, grocery and dollar stores, removing comparisons with drug stores,” Walmart stated in an email to Savings Catcher users.

Walmart has also eliminated produce and bakery items from the program, arguing that they do not allow “like for like” matches with products offered by other retailers.