diff --git a/doc/source/admin/components.rst b/doc/source/admin/components.rst
index fbb8cbc..b3a4c3f 100644
--- a/doc/source/admin/components.rst
+++ b/doc/source/admin/components.rst
@@ -115,6 +115,11 @@
       A list of zookeeper hosts for Zuul to use when communicating
       with Nodepool.
 
+   .. attr:: session_timeout
+      :default: 10.0
+
+      The ZooKeeper session timeout, in seconds.
+
 
 .. _scheduler: