How do you change the code example font size in LaTeX PDF output with Sphinx?

I find the default code example font in the PDF generated by Sphinx to be far too large.

I've tried getting my hands dirty in the generated .tex file inserting font size commands like \tiny above the code blocks, but it just makes the line above the code block tiny, not the code block itself.

I'm not sure what else to do - I'm an absolute beginner with LaTeX.