Even more important: stop using personas, start using actual people. I've experienced many startups make unforced errors by conflating people into personas. A better way is to tag people with attributes, such as specific interests, explicit concerns, tasks to be done, usage goals, learning preferences, and the like.
When you switch from personas to actual people, it opens up many more product experiments-- many of which are surprising and may even feel counter-intuitive to founders. Increase your startup chances of success by carefully connecting with your actual users.