Sen. Kamala Harris (D-Calif.) on Monday unveiled the second major proposal of her presidential campaign: a comprehensive plan designed to punish corporations that don’t provide equal pay for female employees.

Female employees usually bear the burden of suing for relief from pay discrimination in the U.S., often risking retaliation from their bosses by coming forward.

Harris’ proposal, which her campaign called “the most aggressive equal pay proposal in history,” seeks to flip that system on its head. Instead of relying on employees to prove they were discriminated against, corporations would be required to prove that their pay practices are fair. The plan is modeled after a similar first-of-its-kind law that went into effect in Iceland last year.

“It should not be on a working woman to prove it. It should instead be on that large corporation to prove they’re paying people for equal work equally,” Harris said in an interview that aired Monday on CNN.

Under Harris’ plan, companies would be required to obtain an “equal pay certification” from the U.S. Equal Employment Opportunity Commission to prove they pay women equally. They would be required to disclose whether they received that certification on their website’s homepage and to prospective employees.

To meet certification requirements, companies would have to “demonstrate they have eliminated pay disparities between women and men who are doing work of equal value,” per Harris’ campaign. “To the extent pay disparities do exist for similar jobs, companies will be required to show the gap is based on merit, performance, or seniority ― not gender.”

The plan does not stipulate exactly how pay disparities at companies would be assessed, but her campaign pointed to a 2016 payroll data analysis done by Glassdoor of its own workforce. The plan also calls for providing technical assistance to support companies so they can assess and address their pay gaps.