(defun mm-mule-charset-to-mime-charset (charset)
"Return the MIME charset corresponding to the given Mule CHARSET."
- (if (fboundp 'find-coding-systems-for-charsets)
+ (if (and (fboundp 'find-coding-systems-for-charsets)
+ (fboundp 'sort-coding-systems))
(let (mime)
(dolist (cs (sort-coding-systems
(copy-sequence