Default sensu-server log location?

I’m running Sensu in a container and would like to send log output to STDOUT instead of /var/log/sensu. The documentation says,

-l (--log LOG)
The path to the LOG file. Defaults to STDOUT if not provided.

The container is running from a Centos image with a 1:0.27.0 Sensu RPM is installed. The RPM creates a /var/log/sensu directory and drops in a logrotate configuration file to rotate sensu-server.log in that directory.The command line call in /etc/systemd/system/sensu-server.service is,

ExecStart=/opt/sensu/bin/sensu-service start server

This command is not setting the log file to something other than STDOUT. And yet, when sensu-server is started, the log file shows up in /var/log/sensu/sensu-server.log, just where the logrotate file expects it to be.

Is the documentation for the default log setting correct? If not, how does one set STDOUT as the target for log messages?