If I try to load the boldface variant of \mathbb using mathalpha as in the MWE below I get the error:

Package xkeyval: 'oldbold' undefined in families 'mathalfa'.

That option is specified in the mathalpha documentation.


\usepackage[bb=px, oldbold]{mathalpha}


Normal \(\mathbb{A}\)

Bold \(\mathbfbb{A}\)


On a fresh Overleaf document this actually works, even when I load the rest of my preamble. Could it be an installation issue?

  • Yes, it looks like I have an old version installed. The most recent one from CTAN doesn't suffer this issue.
    – seldon
    Commented Jul 10 at 8:43
  • 2
    I’m voting to close this question because the issue was due to outdated software
    – egreg
    Commented Jul 10 at 8:59
  • that's the version shipped with TeX Live as of a couple of months ago, so this is a potentially very useful google result (it certainly would've helped me)
    – seldon
    Commented Jul 10 at 9:03


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