Michael Rubke, a desk attendant at La Rive condo complex in Minneapolis, is fighting for a union against a behemoth building management company, FirstService Residential of Minnesota, that has a near-monopoly on high-rise condos in the Twin Cities. It’s been a difficult battle so far. The unionization campaign is “at square one,” the 41-year-old explained over the phone after working an overnight shift. “They’re pretending we’re not there.”

But that lack of formal union representation did not stop Rubke and his colleagues throughout the Twin Cities from fighting for—and winning—statewide legislation this summer that improves the terms of their jobs, by beating back a little-known provision used to erode the job security of contracted workers.

Under the legislation, which went into effect on July 1, companies in Minnesota are barred from entering into new contracts that contain restrictive covenants, which function like noncompete agreements but have previously slipped past the prohibitions on noncompetes in Minnesota because they have a slightly different structure. Existing restrictive covenants, however, are left in place.