diff --git a/doc/topics/configuration.rst b/doc/topics/configuration.rst
index 0eff5f449f..20a7d7c70b 100644
--- a/doc/topics/configuration.rst
+++ b/doc/topics/configuration.rst
@@ -48,7 +48,8 @@ Default `localhost:8000`
 hostname
 ~~~~~~~~
 
-Defines the hostname.
+Defines the hostname to use when generating a URL when there is no request
+context available, for example during a cron job.
 
 root
 ~~~~