Elon Musk slammed Facebook in a simple response after the vice president of artificial intelligence at Facebook questioned Musk’s knowledge of artificial intelligence.

“Facebook sucks,” Elon Musk wrote in reply to a tweet posted by Jerome Pesenti, who criticized Musk’s warnings about the dangers of artificial general intelligence (AGI).

The tweet Pesenti posted that drew such reply from Musk reads: “I believe a lot of people in the AI community would be ok saying it publicly. @elonmusk has no idea what he is talking about when he talks about AI. There is no such thing as AGI and we are nowhere near matching human intelligence. #noAGI”

The statements follow a CNBC story including interviews with AI researchers who deem Musk’s comments about AI “inappropriate.”

Musk has made his hatred for Facebook very clear in the past.

In February, the CEO spoke out against the firm by urging users to delete their accounts, calling the site “lame.”