Failed to decode downloaded font on Heroku

Question

I'm seeing the following warning in Chrome Developer Tools when I access my JHipster application at http://www.jhipster-book.com. I don't see this error when running locally.

Failed to decode downloaded font: http://www.jhipster-book.com/assets/fonts/sourcesanspro/sourcesanspro.woff

I'm using these same fonts on a client's project (that runs on GAE) and it works fine. It looks like the content-type header is not being set on Heroku. Here's what I see locally:

    HTTP/1.0 200 OK
    Server: SimpleHTTP/0.6 Python/2.7.9
    Date: Fri, 12 Jun 2015 21:57:23 GMT
    Content-type: application/x-font-woff
    Content-Length: 27248
    Last-Modified: Fri, 12 Sep 2014 16:22:14 GMT

And on Heroku:

    HTTP/1.1 200 OK
    Connection: keep-alive
    Server: Apache-Coyote/1.1
    X-Application-Context: application:prod,heroku:56079
    Cache-Control: max-age=2678400000, public
    Pragma: cache
    Expires: Mon, 13 Jul 2015 21:59:11 GMT
    Last-Modified: Fri, 12 Jun 2015 21:47:41 GMT
    X-Content-Type-Options: nosniff
    X-Xss-Protection: 1; mode=block
    Cache-Control: no-cache, no-store, max-age=0, must-revalidate
    Pragma: no-cache
    Expires: 0
    Content-Length: 27247
    Date: Fri, 12 Jun 2015 21:59:11 GMT
    Via: 1.1 vegur

Is there something I have to configure in Heroku for this to work?