diff --git a/README.md b/README.md
index cea2f940..8b2278c3 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ Some features:
 - plain text body
 - HTML body
 - multipart body (plain text + HTML)
-- Markdown to HTML converting
+- Markdown to HTML converting (use `html_body`, not `body`)
 - file attachments (supports globbing)