diff --git a/tex.el b/tex.el
index 9bbfefe3078..4e04b8cbf81 100644
--- a/tex.el
+++ b/tex.el

@@ -4036,7 +4036,7 @@ when MODE is one of the AUCTeX new mode names."

;; Sort it

(message "Sorting %s..." name)

(set local

- (sort (mapcar #'TeX-listify (apply #'append (symbol-value local)))

+ (sort (mapcar #'ensure-list (apply #'append (symbol-value local)))

#'TeX-car-string-lessp))

(message "Sorting %s...done" name)

;; Make it unique

@@ -4889,10 +4889,8 @@ The optional argument EXTRA-DIRS is passed to `TeX-search-files-kpathsea'."

;; Some of these functions has little to do with TeX, but nonetheless we

;; should use the "TeX-" prefix to avoid name clashes.

-(defun TeX-listify (elt)

- "Return a newly created list with element ELT.

-If ELT already is a list, return ELT."

- (if (listp elt) elt (list elt)))

+;; We can use `ensure-list' available with Emacs 28.1:

+(define-obsolete-function-alias 'TeX-listify #'ensure-list "AUCTeX 14.2.0")

(defun TeX-member (elt list how)

"Return the member ELT in LIST. Comparison done with HOW.