I've got Latex's nicefrac working fine for a Latex export. I've put 

#+LaTeX_HEADER: \usepackage{nicefrac}

at the top of my file, and this inlined

$\pi = \nicefrac{C}{d}$

But for an HTML export, it's not seeing it, giving back π=\nicefracCd. Is there anything I can do to get my HTML export to handle nicefrac properly?

LB