A group of SpaceX employees was reportedly fired last week after writing an open letter decrying CEO Elon Musk as a frequent “embarrassment” to the company.

The letter to SpaceX President Gwynne Shotwell says recent actions by Musk, who is also CEO of Tesla Inc., and allegations of sexual harassment against him are harming the rocketry company’s reputation.

“Elon’s behavior in the public sphere is a frequent source of distraction and embarrassment for us, particularly in recent weeks,” the letter says, according to The Verge.

“As our CEO and most prominent spokesperson, Elon is seen as the face of SpaceX — every tweet that Elon sends is a de facto public statement by the company. It is critical to make clear to our teams and to our potential talent pool that his messaging does not reflect our work, our mission or our values.”

SpaceX fired “a number of employees involved” in writing the letter, according to an internal email from Shotwell that called the letter “overreaching activism,” The New York Times reported.