Having a document with numbered headings, when I export it into PDF from Word 2013 all numbering is rendered as bitmaps in the PDF instead of text. This happens regardless if I use the built-in "Export—Create PDF/XPS Document" feature or a PDF printer such as PDFCreator.
The original in Word 2013
The PDF version
How can this behavior be prevented so that Word exports numbering as text and not as raster images?