Apple Inc. unlawfully fired an employee at its headquarters in Cupertino, Calif., over using messaging app Slack to push for workplace changes, a federal labor board official alleged in a complaint announced Friday.

Apple in a statement provided by a spokesperson on Friday said it is committed to maintaining "a positive and inclusive workplace" and takes employee complaints seriously.

The National Labor Relations Board has accused Apple of infringing on its employees’ rights to advocate for better working conditions. In a complaint spotted by Reuters, the agency alleges Apple illegally fired an employee who had used Slack to advocate for workplace changes at the company.

The U.S. National Labor Relations Board (NLRB) says Apple is interfering with workers’ rights to collectively advocate for better working conditions by restricting their use of social media and workplace messaging app Slack,