1 files changed, 1 insertions, 1 deletions

diff --git a/lisp/mail/footnote.el b/lisp/mail/footnote.el
index 327eda11dc5..a1bbf7369b2 100644
--- a/lisp/mail/footnote.el
+++ b/lisp/mail/footnote.el
@@ -348,7 +348,7 @@ Use Unicode characters for footnoting."
 (defconst footnote-hebrew-numeric-regex
   (let ((numchars (string-to-list
                    (apply #'concat (apply #'append footnote-hebrew-numeric)))))
-    (concat (regexp-opt-charset (cons ?' numchars)) "+")))
+    (rx-to-string `(1+ (in ?' ,@numchars)))))
 ;; (defconst footnote-hebrew-numeric-regex "\\([אבגדהוזחט]'\\)?\\(ת\\)?\\(ת\\)?\\([קרשת]\\)?\\([טיכלמנסעפצ]\\)?\\([אבגדהוזחט]\\)?")
 
 (defun footnote--hebrew-numeric (n)