diff --git a/lisp/char-fold.el b/lisp/char-fold.el
index e4c7c3c41e5..ce395ddaab0 100644
--- a/lisp/char-fold.el
+++ b/lisp/char-fold.el
@@ -24,6 +24,8 @@
 
 ;;; Code:
 
+(eval-when-compile (require 'subr-x))
+
 (eval-and-compile
   (put 'char-fold-table 'char-table-extra-slots 1)
   (defconst char-fold--default-override nil)