diff --git a/docs/source/conf.py b/docs/source/conf.py
index cfec6191..58bff26c 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -96,3 +96,7 @@ breathe_projects = dict(
 todo_include_todos = True
 
 subprocess.run('doxygen', shell=True, cwd=source_dir)
+
+# disable epub mimetype warnings
+# https://github.com/readthedocs/readthedocs.org/blob/eadf6ac6dc6abc760a91e1cb147cc3c5f37d1ea8/docs/conf.py#L235-L236
+suppress_warnings = ["epub.unknown_project_files"]