LONDON (AP) — Uber’s chief executive ordered an urgent investigation Monday into a sexual harassment claim made by a female engineer who alleged her prospects at the company evaporated after she complained about advances from her boss.

Travis Kalanick responded on Twitter to an open statement by Susan Fowler Rigetti about her year at the ride-hailing app. In a blog post titled “Reflecting On One Very, Very Strange Year At Uber,” Rigetti says the company’s human resources department ignored her complaints because her boss was a high performer.

“What’s described here is abhorrent & against everything we believe in,” Kalanick tweeted Monday. “Anyone who behaves this way or thinks this is OK will be fired.”

In her blog, Rigetti said she joined Uber as a site reliability engineer in November 2015 in San Francisco. On her first official day with the company, Rigetti says her boss propositioned her in a string of messages on the company chat. As it was “clearly out of line,” she took screen shots of the remarks.

“Upper management told me that he “was a high performer” (i.e. had stellar performance reviews from his superiors) and they wouldn’t feel comfortable punishing him for what was probably just an innocent mistake on his part,” she wrote.

Rigetti, who did not name the manager, left the team. But she said as she tried to progress in the company, she found her way blocked. She alleged sexism was rampant in the company, and that when she pointed that out at a company meeting, she was rebuffed.

In one instance, she said the director of engineering ordered leather jackets for the site’s reliability engineers, but later decided it would only give the jackets to male engineers because there were too few women in the company to qualify for a bulk purchase discount.

“The director replied back, saying that if we women really wanted equality, then we should realize we were getting equality by not getting the leather jackets,” she wrote. “He said that because there were so many men in the org, they had gotten a significant discount on the men’s jackets but not on the women’s jackets, and it wouldn’t be equal or fair, he argued, to give the women leather jackets that cost a little more.”

Kalanick said he has instructed the company’s chief human resources officer to look into the blog post, adding “there can be absolutely no place for this kind of behavior at Uber.”

Rigetti’s remarks will strike a nerve among those trying to bolster the number of women in science and engineering, who have long argued that male-dominated atmospheres are discouraging the talented from seeking careers in the sector.

Rigetti said she temporarily disabled comments on her blog post “because there were too many for me to keep up with.”