diff --git a/doc/user/setup.rst b/doc/user/setup.rst
index dcc7607e48..372494fbce 100644
--- a/doc/user/setup.rst
+++ b/doc/user/setup.rst
@@ -114,6 +114,16 @@ most operating systems is 1024.  If the operator plans to run bgp with
 several thousands of peers then this is where we would modify FRR to
 allow this to happen.
 
+::
+
+  FRR_NO_ROOT="yes"
+
+This option allows you to run FRR as a non-root user. Use this option
+only when you know what you are doing since most of the daemons
+in FRR will not be able to run under a regular user. This option
+is useful for example when you run FRR in a container with a designated
+user instead of root.
+
 ::
 
    zebra_options=" -s 90000000 --daemon -A 127.0.0.1"