Confluence User Macros prints HTML in plain text

[strope.cory]

I am trying to list all of the groups in my confluence instance (6.15) using a previous Velocity + HTML solution at https://community.atlassian.com/t5/Confluence-questions/how-can-i-get-a-listing-of-groups-in-confluence/qaq-p/286568

## Developed by: Davin Studer
## Date created: 04/21/2015
## @noparams
<ul>
#foreach($group in $userAccessor.getGroups())
    <li>$group</li>
#end
</ul> 

However, when I use the above macro, all of the HTML tags are printed in plain text. I have tried this in every Macro Body Processing type, and have enabled the html and html-include modules from the system Confluence HTML Macro add-on.

Is there a way to have the HTML render when using the macro?