The head of OpenAI security systems, Johannes Heidecke, told staff this week that he is leaving the company, WIRED has learned. Heidecke’s departure follows a reorganization that sought to integrate OpenAI’s research and security teams.

In a memo to staff seen by WIRED, research director Mark Chen said OpenAI’s security teams will now report to the company’s vice president of research and chief alignment officer, Mia Glaese, who will take on an expanded role as vice president of research and security. Saachi Jain, who previously led security teams at OpenAI, will become the company’s interim head of security systems, reporting to Glaese.

“Security demands continue to increase: we are training models at a much faster cadence, and in turn, release cycles have been significantly reduced,” Chen said in the memo. “As a result, we have greater security coordination challenges than ever before.”

Heidecke joined OpenAI in 2021 as an AI security analyst. He took over as the company’s chief security systems officer in 2024, after previous director Lilian Weng left to co-found 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 security work is integrated with cutting-edge model development, with an earlier and more direct role in shaping key decisions about models, products and launches. We are excited about this next chapter under Mia Glaese’s leadership in research and security.”

Heidecke’s departure comes as OpenAI attempts to release increasingly capable AI models. Earlier this week, the company launched GPT-5.6, its most capable model to date in agent coding tasks. However, compared to previous models, OpenAI says GPT-5.6 showed worrying forms of misaligned behavior.

Heidecke is the latest security-focused leader to depart from OpenAI in recent days. Earlier this week, OpenAI chief futurist Joshua Achiam also told colleagues he was leaving the company after nine years researching security.

It’s not just OpenAI’s security teams that are changing, either. Earlier this week, OpenAI’s executive director of AGI implementation, Fidji Simo, told staff that he would be stepping down from his role after an extended medical leave. The company said Greg Brockman would continue to lead OpenAI’s product teams, a task he had been assigned in his absence, but would also be responsible for commercialization strategy.