In November, Microsoft took a $480 million contract with the U.S. Army to supply prototypes for the Integrated Visual Augmentation System (IVAS). It may mean big money for the company, but its employees are not impressed.

A group of more than 100 Microsoft employees are now criticizing the company’s plans and calling for Microsoft to end its military contract, TechCrunch reported.

The Verge reported the letter — addressed to CEO Satya Nadella and president Brad Smith — said, “We are alarmed that Microsoft is working to provide weapons technology to the US military, helping one country’s government ‘increase lethality’ using tools we built.”

A government description of the IVAS program stated it was meant to “increase lethality by enhancing the ability to detect, decide, and engage before the enemy,” according to Bloomberg. Through the program, Microsoft would provide more than 100,000 headsets for combat and training.

In the letter, employees went on to say, “We did not sign up to develop weapons and we demand a say in how our work is used.”

This isn’t the first time a big tech company’s employees have pushed back against company involvement with the military. Once, Google prompted response from its employees after it began working to deploy computer algorithms in war zones with the U.S. Department of Defense’s Project Maven.

“Building this technology to assist the US government in military surveillance — and potentially lethal outcomes — is not acceptable,” Google employees wrote in a letter, eventually forcing the company to drop the contract.

There are dangerous implications if tech is allowed to continue collaborating with the military. As people worry about the role tech can play in surveillance at home, military partnerships should be understood as furthering surveillance abroad.

Back in October, Microsoft’s president defended the company’s pursuit of military projects.

“We believe in the strong defense of the United States and we want the people who defend it to have access to the nation’s best technology, including from Microsoft,” Smith wrote in a blog post.

Microsoft employees, however, say “Intent to harm is not an acceptable use of our technology.”