WWW subdomain redirects to default site instead of virtual host

I am hosting multiple websites on an instance of OS X Server 4.0 with an issue. I have a default personal site that is available on the normal domain and the www subdomain. I tried to configure other sites to have that similar result also. However, I am running into a problem. My virtual hosts (other sites) have the www subdomain configured in the DNS records. I configured my Virtual Hosts in OS X Server with 0 additional domains, redirects, or aliases. All other settings are also left default.

The DNS on OS X Server is configured correctly as well. When I try to access http://example.com/ it sends me to the Virtual Host correctly. However, when I do http://www.example.com/ it sends me to the Server Default website, which is my personal site. The only way I can fix this is to add another website using the www.example.com into the list.

Is there another way to fix this instead of adding another site to the list?