diff --git a/src/docs/user/configuration/managing_daemons.diviner b/src/docs/user/configuration/managing_daemons.diviner
--- a/src/docs/user/configuration/managing_daemons.diviner
+++ b/src/docs/user/configuration/managing_daemons.diviner
@@ -43,6 +43,10 @@
   - **phd launch** to launch individual daemons; and
   - **phd debug** to debug problems with daemons.
 
+NOTE: The daemons need to run as the daemon user that you have configured in the
+`phd.user` option. The `phd start` command does not enforce this, so you should
+execute the `phd` command as the configured daemon user.
+
 NOTE: When you upgrade Phabricator or change configuration, you should restart
 the daemons by running `phd restart`.