diff --git a/lisp/org-html.el b/lisp/org-html.el
index 6e3bc1939..b77583492 100644
--- a/lisp/org-html.el
+++ b/lisp/org-html.el
@@ -565,6 +565,7 @@ a file."
("<" . "<")
(">" . ">"))
"Alist of characters to be converted by `org-html-protect'."
+ :group 'org-export-html
:type '(repeat (cons (string :tag "Character")
(string :tag "HTML equivalent"))))