Login window doesn't display name and password fields after startup, but will after subsequent logouts

I have a MacBook Pro (Retina, 13-inch, Early 2015) running OS X Yosemite 10.10.3. I have set the login window to display name and password fields so that people can login to our Active Directory. But when I start the computer, it still displays the list of users locally on this computer. However, if I login to a local account and log back out, it now displays the name and password fields. How do I make it so that the name and password fields are displayed after startup?