How to change the font size in tkinter.filedialog.askopenfilename?

I am using tkinter.filedialog.askopenfilename in Python to select a file. How do I change the font size for the file list displayed? I have found answers on StackOverflow on how to change the font of some items on the display (for example here), but do not know the name of the ttk widget that is used for the file list.