Include template from another template in sails.js

I have created a sails.js template: templates/box.ejs

<div id="<%= box_id%>" class="<%= box_class %>">
    <% if(box_title || box_title_icon) {%>
        <div class="header">
            <% include icon%> <---- HERE
            <span class="title"><%= box_title %></span>
            <hr>
        </div>
    <% } %>
    <div class="content">
        <%= typeof box_content == 'function' ? box_content() : box_content%>
    </div>
</div>

In this template I try to include another template file called icon.

But I get this error generated by sails grunt JST task:

error: Grunt ::  Aborted due to warnings.
 Running "jst:dev" (jst) task

>> SyntaxError: Unexpected identifier

Warning: JST failed to compile. Use --force to continue.

Is it even possible to do what I'm trying to do?