Microsoft workers have released a letter protesting the company’s work with oil companies, and say they’ve been made “complicit” in contributing to climate change.

“If we want to make real impact, all of us need to mobilize, work together, and demand a fundamental change in Microsoft’s priorities,” the workers write in the letter.

“All of us need to mobilize”

As noted by Gizmodo, the letter followed an announcement earlier this week that Microsoft would partner with oil companies, including Chevron, to “accelerate creation of innovative petrotechnical and digital technologies.”

The letter from employees hammered the partnership, saying “it’s no longer possible for us to ignore Microsoft’s complicity in the climate crisis.”

The letter comes as workers around the world prepare to walk off the job tomorrow to push for action on climate change. Employees at Amazon, Google, and Microsoft have all said they plan to join the Global Climate Strike. This morning, Jeff Bezos, facing protests from employees, announced steps that Amazon would take to combat climate change.

Microsoft did not immediately respond to a request for comment on the letter.

“Big Oil should not have the luxury of choosing the most convenient and profitable service,” the letter concludes. “It is imperative that all tech companies stand together, denounce the usage of Cloud and AI services for non-renewable energy extraction, and work together to put an end to fossil fuel consumption.”