Elon Musk on Monday targeted Apple and OpenAI in an antitrust lawsuit alleging that the iPhone maker and the ChatGPT maker are teaming up to thwart competition in artificial intelligence.

Billionaire entrepreneur Elon Musk’s artificial intelligence startup xAI sued Apple (AAPL) and ChatGPT maker OpenAI in U.S. federal court in Texas on Monday, accusing them of illegally conspiring to thwart competition for artificial intelligence.

Musk’s social media platform X and his AI startup xAI accused Apple, which has a deal to integrate OpenAI’s chatbot in its products, of deprioritizing competitors in its apps marketplace, even though several ChatGPT rivals have hit the No. 1 spot recently.