Microsoft on Tuesday said it has changed some key terms of a deal with OpenAI after the ChatGPT creator announced a joint venture with Oracle and Japan’s SoftBank Group to build up to $500 billion of new AI data centers in the United States.

The new agreement “includes changes to the exclusivity on new capacity, moving to a model where Microsoft has a right of first refusal (ROFR),” Microsoft says. “To further support OpenAI, Microsoft has approved OpenAI’s ability to build additional capacity, primarily for research and training of models.”