Head of OpenAI security systems maker Johannes Heidecke told employees this week he was leaving the company, WIRED has learned. Heidecke’s departure follows a reorganization that aimed to integrate OpenAI’s security and research teams.
In a memo to employees obtained by WIRED, chief research officer Mark Chen said that OpenAI’s security teams will now report to the company’s vice president of research and head of alignment, Mia Glaese, who will assume the expanded role of vice president of research and security. Saachi Jain, who previously led security teams at OpenAI, will become interim head of security systems at the company and will report to Glaese.
“Security requirements continue to increase – we are training models at a much faster pace, and release cycles have in turn significantly shortened,” Chen said in the note. “As a result, we have greater security coordination challenges today than ever before.”
Heidecke joined OpenAI in 2021 as an AI security analyst. He took over as head of the company’s security systems in 2024, after the previous head, Lilian Weng, left to found the Thinking Machines Lab with other OpenAI researchers.
“We are grateful for Johannes’ contributions to OpenAI,” Chen said in a statement to WIRED. “It is important that our safety work is integrated into the development of pioneering models, with an earlier and more direct role in shaping key model, product and launch decisions. We are excited about the next chapter under Mia Glaese’s leadership in research and safety.”
Heidecke’s departure comes as OpenAI tries to release increasingly effective artificial intelligence models. Earlier this week, the company launched GPT-5.6, its most powerful model yet for agent-based coding tasks. However, compared to previous models, OpenAI claims that GPT-5.6 showed regarding forms of inappropriate behavior.
Heidecke is the latest security leader to leave OpenAI in recent days. Earlier this week, OpenAI’s chief futurist, Joshua Achiam, also told colleagues he would be leaving the company after nine years of security research.
It’s not just OpenAI’s security teams that are changing. Earlier this week, OpenAI’s general manager of AGI implementation, Fidji Simo, told employees that she would be stepping down from her position after an extended medical leave. The company said Greg Brockman will continue to lead the OpenAI product teams, a role he was assigned to in its absence, but will also handle go-to-market strategy.