Brian Acton, a co-founder of WhatsApp and financier of Signal, is becoming Signal's interim CEO as Moxie Marlinspike steps down as Signal's CEO over the next month, according to a blog post published Monday by Marlinspike.

The news signals a shakeup at an organization that has evolved far beyond its barebones team to one that hires dozens of people, and which continues to launch new features. Last week, WIRED reported that Signal's feature for transferring cryptocurrency between users had gone worldwide.