Faculty, students and alumni at Harvard Business School signed an open letter to Amazon Friday urging better working conditions for Black employees and supporting an Amazon manager and Harvard Business alumna who is suing the e-commerce giant.

The Amazon manager, Charlotte Newman, filed a lawsuit in March over allegations of racial discrimination and sexual harassment from coworkers and superiors at Amazon’s corporate offices.

“Those of us who know Charlotte know her as a woman of integrity, intelligence and strong work ethic. We know her as a person who has long demonstrated a commitment to improving the lives of others,” the Harvard Business letter states.

The letter, signed by more than 220 members of the Harvard Business community as of Friday morning, urges Amazon to make changes toward being a “fairer, safer and more diverse workplace for all of its employees.”

In response to the letter, an Amazon spokesperson said company employees “do not tolerate discrimination or harassment of any kind,” and defended its handling of Newman’s sexual harassment claim and discrimination allegations.