Chapter names are not respected by rendered EPUB.

[risograph]

Hello. I am converting old books into EPUBs and many of them use Roman numerals to number their chapters. I want to respect this decision, so when creating multiple files for multiple chapters, I precede them with a chapter title (ex. # VIII #). It seems to work fine, but when it renders, crowbook automatically adds a "Chapter [number]" before the Roman number. How can I disable this behavior?