--- js/gdm/loginDialog.js.shells	2013-07-31 02:23:04.000000000 +0400
+++ js/gdm/loginDialog.js	2013-07-31 10:31:18.338968456 +0400
@@ -241,6 +241,12 @@
         if (user.locked)
            return;
 
+	let userShell = user.get_shell();
+
+	if (userShell == '/dev/null' ||
+	   userShell == '/bin/false')
+	    return;
+
         let userName = user.get_user_name();
 
         if (!userName)