WhatsApp is today making its new two-step verification feature available to all.

Once enabled, WhatsApp will require you to enter a six-digit passcode when you attempt to verify your phone number.

WhatsApp has been testing two-step verification for several months in an effort to make its app safer. It’s now rolling out to all 1.2 billion users on Android, iOS, and Windows. However, it’s optional and disabled by default, which means you’ll need to enable it yourself.

To do this, go into the settings menu inside WhatsApp, then tap the Account option. Select Two-step verification, then choose Enable. You will be asked to create a six-digit passcode, which you will then need to enter every time you verify your phone number.

This makes it even more difficult for others to gain access to your WhatsApp account. However, it could be just as hard for you to get in if you forget your six-digit code, so ensure that you use something memorable.

To help you remember the code over time, WhatsApp will periodically ask you to enter it. There is no way to disable this without deactivating two-step verification altogether, the company says.

“Upon enabling this feature, you can also optionally enter your email address,” WhatsApp explains. “This email address will allow WhatsApp to send you a link via email to disable two-step verification in case you ever forget your six-digit passcode.”

WhatsApp does not verify this email address to confirm its accuracy, however, so be sure you enter it correctly the first time. For more information about two-step verification, check out WhatsApp’s official FAQ.