Every few days seems to bring another recall of contaminated food. Walmart thinks it’s found a solution to respond quickly to such incidents: the blockchain.

In the past couple of years, the blockchain has gone from arcane technology with a disruptive potential to a buzzword that often seems overhyped. But Walmart is introducing what could be a promising use case for the blockchain. It’s asking suppliers of lettuce and leafy greens to use the blockchain to trace their products through Walmart’s supply chain.

2018 has seen a disturbing increase in food recalls. Last month, Cargill recalled 25,000 pounds of beef after an E. coli outbreak, and this month it recalled another 132,000 pounds. Salmonella outbreaks have caused recalls of raw turkey, Kellogg’s Honey Smacks, pre-cut melon and more than 200 million eggs.

In April, an E. coli outbreak in romaine lettuce from Yuma, Ariz., left 150 people sick, caused huge losses to growers, and disrupted supply chains to restaurants and grocery stores. The turmoil dragged on for weeks as regulators and companies scrambled to find the source and extent of the contaminated lettuce.

Walmart said the romaine E. coli scare is exactly the kind of scenario the blockchain can address. The company piloted a program with IBM’s Food Trust, a blockchain initiative that creates a massive digital ledger that tracks food from the farm—where it’s logged in on handheld devices—to processing facilities, then to distributors and the grocery shelves. The result is a way of tracking food that can trace bacteria outbreaks quickly back to the source.

“The way it works today is a paper-trail exercise that sometimes runs dry,” said Frank Yiannis, vice president of food safety at Walmart. “With the traceability of blockchain, we can scan product and trace it back to source with precision in seconds instead of days or weeks.”

Walmart is asking its direct suppliers of leafy greens to adopt the IBM Food Trust network by Jan. 31, 2019, and for other suppliers to join by the following September. Depending on the success of the program, other food products may later be traced on the blockchain.

“In the future, a customer could scan a bag of salad and see if it’s involved in a recall or not,” Yiannis said.