The gig economy’s work force is fighting back, and in some cases, it’s winning.

On Wednesday, Instacart, the Silicon Valley upstart that delivers groceries and other household items to customers through an app, reversed a tipping policy that had outraged workers, who accused the $7 billion company of cheating them out of rightfully earned wages.

“We heard loud and clear the frustration when your compensation didn’t match the effort you put forth,” Apoorva Mehta, Instacart’s chief executive, wrote in an open letter to Instacart’s contract workers, known as shoppers.

Instacart’s workers had taken to Reddit forums and private Facebook groups to express their anger with the policy, which counted tips toward the guaranteed minimum payments the company offered to shoppers. In some cases, the more customers tipped, the less Instacart paid them.

“It’s offensive, it’s unethical, and in this climate it’s a very dumb thing to do,” Matthew Telles, an Instacart courier in Chicago, said this week before the reversal.