bundles error with 'exports is not defined' on html imports

[MoonStorm]

When attempting to bundle html files for production, I get the following construct in the js file:

System.register("app/components/component.html", [], function (_export, _context) {
  "use strict";
  return {
    setters: [],
    execute: function () {
      Object.defineProperty(exports, "__esModule", { value: true });
      exports.__useDefault = true;
      exports.default = "<div>....</div>";
    }
  };
});

Bundles get generated but they fail with an 'exports is not defined' error when referenced in the browser.

The dev/build config uses the typescript plugin and the text plugin, both working fine otherwise.

[guybedford]

This seems like a duplicate of systemjs/plugin-text#47, moving discussion there.