Facebook’s parent company Meta is supporting Elon Musk’s effort to block OpenAI’s conversion from a non-profit company into a for-profit one.

As reported by The Wall Street Journal, Meta sent a letter to California Attorney General Rob Bonta arguing that allowing the shift would have “seismic implications for Silicon Valley.” And while the company asked Bonta to take “direct action,” it also said Musk and former OpenAI board member Shivon Zilis “are qualified and well-positioned to represent the interests of Californians in this matter.”

“If OpenAI’s new business model is valid, non-profit investors would get the same for-profit upside as those who invest the conventional way in for-profit companies while also benefiting from tax write-offs bestowed by the government,” Meta wrote.

Meta has become one of OpenAI’s big competitors in the AI market. Musk, meanwhile, was originally a co-founder at OpenAI before eventually splitting from the company, starting rival xAI, and taking legal action that includes seeking an injunction to stop its transition into a for-profit. (Zilis is also a plaintiff in Musk’s lawsuit.)

OpenAI responded by publishing emails and texts from Musk and arguing that “he should be competing in the marketplace rather than the courtroom.”