The U.S. Senate added a measure to its spending bill Thursday that would guarantee basic workplace accommodations for pregnant employees, a major victory for worker advocates who have spent years lobbying for the change.

The legislation, known as the Pregnant Workers Fairness Act, was attached as an amendment to the omnibus spending bill being negotiated in the upper chamber. The final package still needs approval from both the Senate and House before going to President Joe Biden’s desk.

The pregnant workers measure would require employers to make “reasonable” accommodations for employees affected by pregnancy or childbirth, unless it imposes an “undue hardship” upon the business. The legislation was modeled on the Americans with Disabilities Act, and tracks with several state laws already passed to bar discrimination against pregnant workers.

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