Amazon was praised by some of its harsher critics for raising the minimum wage for its workers in the United States and United Kingdom on Tuesday. The new $15 rate for U.S. employees, in particular, could be seen as a breakthrough for the “Fight for $15” movement. However, criticism mounted for the company later in the week when it was revealed that Amazon employees would lose valuable stocks and bonuses as part of the wage increase, according to The Guardian.

Under the previous pay structure, Amazon warehouse and other hourly workers reportedly got a single company share at the end of each year of employment. They were then eligible for an extra share every five years. Since Amazon shares are currently worth around $2,000 USD each, they could theoretically be valuable incentives for workers to stay with the company for extended periods of time. 

Amazon confirmed warehouse workers would no longer get those stock options but would allow employees to buy shares at a discount.

Additionally, workers will allegedly no longer be eligible for cash bonuses based on productivity. Amazon denied the existence of such bonuses, but British trade union GMB claimed the benefits were being pulled. GMB called the new pay structure a “stealth tax” on hourly workers.

GMB and other labor advocates criticized Amazon for the move, as hourly employees could theoretically make less money than before despite the wage increase. When explaining the changes to its employees, Amazon said the affected workers would prefer the “predictability and immediacy” of bigger paychecks over stock money they may never see.

However, given that Amazon CEO Jeff Bezos is the richest man in the modern history and Amazon’s market value hovers around $1 trillion, critics argue the company could increase wages while keeping a bonus structure in place.

Amazon has come under fire in recent years after accusations of poor working conditions and low wages at its fulfillment centers. Workers in different parts of the world went on strike during the company’s Prime Day promotion over the summer. Sen. Bernie Sanders (I-VT) has been one of the company’s bigger critics in Washington, though he praised Amazon after the wage increase.