Shortly after Elon Musk made a surprise $97 billion bid for OpenAI’s assets on Monday, its CEO Sam Altman told staff in a message that its board of directors intends to make clear it has no interest in Musk’s “supposed ‘bid’” and that the offer wasn’t in the interest of OpenAI’s mission to develop advanced artificial intelligence for all of humanity, according to a person who saw the message.

The letter indicates that OpenAI’s 10-person board is backing Altman in his fight against Musk’s monthslong effort to prevent the for-profit arm of OpenAI, which develops ChatGPT and other products, from getting out from under the control of OpenAI’s nonprofit by converting to a public benefit corporation. Musk is arguing that the nonprofit will be shortchanged by the conversion.