Jspm bundling dialog resources

When using jspm bundling with the aurelia-dialog plug-in I receive an error. It appears that dialog resources are not being bundled but aside from that are not loaded at all.

system.src.js:1612 Uncaught (in promise) TypeError: t.substr is not a function
at _ (system.src.js:1612)
at a. (system.src.js:2475)
at a.normalizeSync (system.src.js:4457)
at system.src.js:3302
at eval (jspm-bundle.js:1)
at new Promise ()
at Object.ux-dialog (jspm-bundle.js:1)
at eval (jspm-bundle.js:1)
at Array.map ()
at a._apply (jspm-bundle.js:1)

You’ll need to provide at least JSPM version, dialog version and the configuration you are using.
Also I’m assuming the stack trace is from bundling(build time)?