After a lengthy consideration, the National Labor Relations Board has ruled that Amazon’s “captive-audience meetings” are a violation of the National Labor Relations Act. These are mandatory meetings where an employer shares its stance on unionization.

“Ensuring that workers can make a truly free choice about whether they want union representation is one of the fundamental goals of the National Labor Relations Act. Captive audience meetings—which give employers near-unfettered freedom to force their message about unionization on workers under threat of discipline or discharge—undermine this important goal,” Chairman Lauren McFerran said of the ruling. “Today’s decision better protects workers’ freedom to make their own choices in exercising their rights under the Act, while ensuring that employers can convey their views about unionization in a noncoercive manner.”

The decision noted that employers may hold meetings about unionization as long as workers receive advanced notice about the topic, are told that attendance is voluntary and without consequences for opting not to participate, and that attendance records are not kept.

Today’s ruling centers on Amazon, which has a rocky history with its employees’ efforts to organize and with the NLRB. However, the decision could impact other big tech firms that have followed similar practices around unionization.