arangodb · Simran-B · Aug 12, 2021 · Jun 29, 2021 · Jul 1, 2021 · Aug 12, 2021
diff --git a/3.9/programs-arangod-server.md b/3.9/programs-arangod-server.md
@@ -356,6 +356,17 @@ If set to *false* only use the external authentication system. If
 
 The default value is *true*.
 
+## Timeout for web interface sessions
+
+`--server.session-timeout value`
+
+The timeout value for web interface sessions is now configurable via the
+startup option `--server.session-timeout`. The value for the option can
+be specified in seconds. The default timeout value for web interface
+sessions is one hour in ArangoDB 3.9.
+
+Previous versions of ArangoDB had a longer, hard-coded timeout.
+
 ## Server threads
 
 `--server.minimal-threads number`

diff --git a/3.9/release-notes-upgrading-changes39.md b/3.9/release-notes-upgrading-changes39.md
@@ -22,6 +22,15 @@ runtime.
 Startup options
 ---------------
 
+### Timeout for web interface sessions
+
+The timeout value for web interface sessions is now configurable via the
+startup option `--server.session-timeout`. The value for the option can
+be specified in seconds. The default timeout value for web interface
+sessions is one hour in ArangoDB 3.9.
+
+Previous versions of ArangoDB had a longer, hard-coded timeout.
+
 ### Disallowed usage of collection names in AQL expressions
 
 The startup option `--query.allow-collections-in-expressions` added in 3.8.0