diff --git a/src/pages/self-hosting/configuration/envars.mdx b/src/pages/self-hosting/configuration/envars.mdx
index 734d49cd..f554b84a 100644
--- a/src/pages/self-hosting/configuration/envars.mdx
+++ b/src/pages/self-hosting/configuration/envars.mdx
@@ -1085,6 +1085,15 @@ These variables are not required if using the suggested [docker-compose template
 
     Required by the [`backend`](https://hub.docker.com/r/phasehq/backend) and [`worker`](https://hub.docker.com/r/phasehq/backend) containers.
   </Property>
+  <Property name="SESSION_LIFETIME_HOURS" type="number (Optional)">
+    How long a session lasts after sign-in, in hours. The time is counted from sign-in and activity does not extend it. When it ends, the user is asked to sign in again. Defaults to `24`.
+
+    Must be a whole number, `1` or more. The backend does not start with any other value.
+
+    Example: `12`
+
+    Referenced by the [`backend`](https://hub.docker.com/r/phasehq/backend) container.
+  </Property>
 
   <Property name="GUNICORN_WORKERS" type="number (Optional)">
     The number of Gunicorn worker processes for handling requests in the backend.