diff --git a/lisp/ox-html.el b/lisp/ox-html.el
index 5df9c2a21..568217563 100644
--- a/lisp/ox-html.el
+++ b/lisp/ox-html.el
@@ -45,6 +45,7 @@
(declare-function htmlize-region "ext:htmlize" (beg end))
(declare-function org-pop-to-buffer-same-window
"org-compat" (&optional buffer-or-name norecord label))
+(declare-function mm-url-decode-entities "mm-url" ())
;;; Define Back-End