Elon Musk and Mark Cuban are still not done with their beef over corporate diversity, equity, and inclusion (DEI) efforts.

On Monday, Musk criticized a diversity goal set by United Airlines’ pilot training academy, United Aviate Academy. The airline wanted its academy to have “50% of enrolled students who are women and/or people of color.”

“The airline industry can’t find enough qualified pilots even without insane DEI requirements!” Musk wrote on X.

Musk’s response was later rebutted by Cuban, who told Musk that the goal applied to the training school and not the airline itself.

“Once they graduate, it’s a multi-year process to have an OPPORTUNITY to pilot for United,” Cuban wrote.

“Since I’m a nice guy and want you to be fully informed, I’ll share with you the benefit of the 60 seconds I spent looking for how the program works. BTW, looks like multiple layers of merit-based evaluations before they can fly for United…,” Cuban continued while attaching a link to the academy’s website.

Musk, however, didn’t agree with Cuban’s points.

“Mark Cuban is a racist,” Musk told a user named “The Rabbit Hole” on X.

Cuban had echoed his earlier points when “The Rabbit Hole” questioned his rebuttal to Musk.

“The only way to prove he is not racist AND sexist is to put an Asian woman and a white woman on his basketball team!” Musk added, reiterating his suggestion for Cuban’s NBA team, the Dallas Mavericks.

Cuban told Business Insider by email that he didn’t have further comments on Musk’s remarks.

DEI has become a major point of contention among business executives like Musk and Cuban.

Fund manager Bill Ackman called attention to the practice last week, saying that it was “racist because reverse racism is racism.”

Musk agreed with Ackman, calling DEI “just another word for racism.”

Cuban, on the other hand, felt that Musk was ignoring the benefits of DEI.

“You may not agree, but I take it as a given that there are people of various races, ethnicities, orientation, etc that are regularly excluded from hiring consideration,” Cuban wrote in a series of posts on X.

“By extending our hiring search to include them, we can find people that are more qualified. The loss of DEI-Phobic companies is my gain,” Cuban continued.

Representatives for Musk did not immediately respond to a request for comment from Business Insider sent outside regular business hours.