I am using \usepackage[left]{showlabels} to print labels for my equations.

For example, I have an equation as:

x = a + b

The label is printed as:

enter image description here

Sometimes the label names are long so I wanted to change the font size, I did that using the following line:


However, the underscore "_" in my label name gets replaced after I change the fontsize.

enter image description here

There is no more "_" in the printed label. What is going on?

  • 2
    Show a complete example. That makes it more easier to test your issue. Commented Jan 30, 2019 at 19:18
  • \documentclass{article} \usepackage[left]{showlabels} \renewcommand{\showlabelfont}{\tiny} %COMMENT AND UNCOMMENT \begin{document} \begin{equation} x = a + b \label{eqn:a_b} \end{equation} \end{document}
    – Alex
    Commented Jan 30, 2019 at 19:24

1 Answer 1


The default definition uses the typewriter font which with OT1 is slightly differently encoded as the roman font. Either add \ttfamily, or load T1-encoding (recommended anyway) or both.


\begin{equation} x = a + b \label{eqn:a_b} \end{equation} 

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