Attorneys for two former Avon employees have filed what they say is the first class-action lawsuit on behalf of women who pump breast milk at work.

One of the plaintiffs is Olivera Krstanoska, a microbiologist who worked at Avon’s Global Research & Development Center in New York from 2014 to 2016. Krstanoska claims her coworkers at Avon harassed her when she became pregnant with her first child and that the treatment only worsened when she gave birth to her second.

In a complaint filed Tuesday in federal court in Manhattan, Krstanoska claims her supervisor and coworkers made her feel “marginalized and penalized” for taking short breaks to pump breast milk, even though New York Department of Labor regulations entitle new mothers to 20-minute breaks every three hours. Her coworkers would mock her for pumping at work, even asking her if she was doing so in order to have “milk for her cereal,” she alleges.

In addition, Krstanoska claims the company failed to provide her a private place to refrigerate her breast milk, instead telling her to store it in the lab refrigerator. As a result, she says, she chose to stop breastfeeding her baby months before she originally intended.

An Avon spokesperson said the company “strongly denies” claims of discrimination. In an emailed statement, the spokesperson pointed to the company’s “generous” maternity leave and “well-equipped mother’s rooms.”

“As a preeminent employer of women, with a workforce comprised of more than two-thirds women, we understand the particular needs working mothers have, and we are committed to supporting them before, during, and after maternity leave,” the spokesperson said.

Krstanoska joins an existing suit filed by Caroline Ruiz, a former Avon executive who claims Avon fired her for being pregnant. The complaint filed Tuesday morning seeks to be certified as a class action on behalf of all pregnant and breast-pumping Avon employees.

The women’s attorney, Jeanne Christenson, said she believes this is the first suit ever filed in the United States on behalf of women who pump breast milk as a class. She told The Daily Beast she decided to highlight pumping because the issue “continues to penalize women at work.”

“Male employees never pay a penalty for their child being granted the benefit of breast milk,” she said in an email. “Women should not lose ground professionally for such a decision. Men need to speak up and refuse to watch female co-workers be subjected to outdated and cruel bias.”