Salesforce Inc. co-founder and Chief Executive Marc Benioff warned Tuesday that the company’s upcoming Dreamforce conference could be its last in San Francisco if it’s affected by the city’s homelessness and open drug use.

San Francisco is counting on the huge conference, expected to draw about 40,000 people, to help reinvigorate its struggling downtown and inject about $57 million into the local economy. Salesforce is the city’s largest private employer.

“If this Dreamforce is impacted by the current situation with homelessness and drug use, it may be the last Dreamforce” in the city, Benioff told the San Francisco Chronicle on Tuesday. While there apparently have not been any prior major incidents involving the conference, Benioff told the Chronicle in 2018 that some attendees had complained about conditions in the city.

Over the years, Benioff and Salesforce have donated tens of millions of dollars to homeless services and housing in San Francisco, including financially backing a ballot measure in 2018 to raise the city’s business tax to help fund homelessness programs.