In a surprising show of filibuster-proof, bipartisan support, the U.S. Senate on Thursday passed a budget amendment to let workers earn up to seven days of paid sick leave per year.

The amendment, introduced by Sen. Patty Murray (D-WA), is similar to the Healthy Families Act, which Murray and Rep. Rosa DeLauro (D-CT) reintroduced this year in Congress. That measure would let workers at companies with more than 15 employees earn up to seven job-protected paid sick days per year; employees at smaller companies could earn up to seven unpaid job-protected days.

Those days can be used to care for oneself or a family member during an illness, or to recover and seek assistance after an incident of domestic violence or sexual assault.

The amendment received 61 votes, including 15 Republicans. It only needed a simple majority to be adopted, but the vote count suggests there could be a filibuster-proof majority in the Senate to pass the stand-alone Healthy Families Act, if the amendment isn’t adopted as part of the final budget passed by both chambers and signed by the president.

“It’s a strong showing, and we certainly weren’t expecting anything like that, to be honest,” a Senate Democratic aide told Rewire. “We were hopeful, certainly, but unfortunately this legislation hasn’t always gotten the bipartisan support you’d hope for.”

The vote was part of a marathon “vote-a-rama” session to consider hundreds of amendments to the Senate’s budget.

The budget is non-binding, so there’s no guarantee any of its provisions will become law. But it’s an important indicator of policy priorities—since these votes will be fodder for campaign ads, they are telling signs of which issues lawmakers want to go on record as supporting or opposing.

Patrick Toomey (R-PA) and Ron Johnson (R-WI), both considered vulnerable in 2016, changed their votes at the last minute. Both of their offices said the initial “no” vote was a mistake.

On Toomey’s home turf, Philadelphia recently became the 17th U.S. city to pass a paid sick leave law. State and local laws mandating paid leave have exploded in just the last few years as advocates have convinced lawmakers of the benefits—happier and more productive workers who won’t infect others when they come to work sick, and all without harming business interests.

“To see 61 senators—Democrats and Republicans—go on record in support of paid sick days is a clear sign that elected officials are hearing from their constituents and taking note of the many cities and states that are adopting paid sick days laws, which are working well for businesses, economies, workers and families,” Debra L. Ness, president of the National Partnership for Women and Families, said in a statement.

Ness called the vote a “milestone” and a “sign of progress in establishing family-friendly workplace policies at the federal level.”

Advocates consider paid sick days to be crucial for women’s equality, since women are less likely than men to have paid sick days, yet 80 percent of mothers take responsibility for a child’s doctor visits.

It’s also an issue of economic fairness overall. Forty-three million Americans don’t get a single paid sick day, and low-wage workers, including food servers, overwhelmingly lack them.

“I am thrilled that the Senate showed strong support today for expanding access to paid sick days and giving more families some much-needed economic stability,” Murray said following the vote. “No worker should have to sacrifice a day’s pay, or their job altogether, just to take care of themselves or their sick child.”