diff --git a/tex.el b/tex.el
index 394814e..3b54d79 100644
--- a/tex.el
+++ b/tex.el
@@ -716,18 +716,57 @@ overlays."
 edit-utils >= 2.32 for XEmacs.")))
 
 (if (fboundp 'completing-read-multiple)
-    (defun TeX-completing-read-multiple
-	(prompt table &optional predicate require-match initial-input
-		hist def inherit-input-method)
-      "Like `completing-read-multiple' which see.
-Ensures that empty input results in nil across different emacs versions."
-      (let ((result (completing-read-multiple prompt table predicate
-					      require-match initial-input
-					      hist def inherit-input-method)))
-	(if (equal result '("")) nil result)))
+    (if (< emacs-major-version 24)
+	;; GNU Emacs < 24
+	(defun TeX-completing-read-multiple
+	    (prompt table &optional predicate require-match initial-input
+		    hist def inherit-input-method)
+	  "Like `completing-read-multiple' which see.
+Ensures that empty input results is nil across different emacs versions."
+	  (let ((result (completing-read-multiple prompt table predicate
+						  require-match initial-input
+						  hist def inherit-input-method)))
+	    (if (equal result '("")) nil result)))
+      ;; GNU Emacs >= 24
+      (defun TeX-completing-read-multiple
+	  (prompt table &optional predicate require-match initial-input
+		  hist def inherit-input-method)
+	"Like `completing-read-multiple' which see.
+Ensures that empty input results is nil across different emacs versions."
+	;; Based on implementation in lisp/emacs-lisp/crm.el in Emacs git
+	;; revision 327f1f6f6d934e58921179275547b2d09f219f32 (Sun, 17 Mar 2013
+	;; 00:19:09 +0000)
+	(unwind-protect
+	    (progn
+	      (add-hook 'choose-completion-string-functions
+			'crm--choose-completion-string)
+	      (let* ((minibuffer-completion-table #'crm--collection-fn)
+		     (minibuffer-completion-predicate predicate)
+		     ;; see completing_read in src/minibuf.c
+		     (minibuffer-completion-confirm
+		      (unless (eq require-match t) require-match))
+		     (crm-completion-table table)
+		     (map (if require-match
+			      crm-local-must-match-map
+			    crm-local-completion-map))
+		     ;; If the user enters empty input, `read-from-minibuffer'
+		     ;; returns the empty string, not DEF.
+		     (input (read-from-minibuffer
+			     prompt initial-input map
+			     nil hist def inherit-input-method))
+		     resul)
+		(and def (string-equal input "") (setq input def))
+		;; Make sure to return nil with empty input.
+		(if (equal (setq result (split-string input crm-separator))
+			   '(""))
+		    nil
+		  result)))
+	  (remove-hook 'choose-completion-string-functions
+		       'crm--choose-completion-string))))
+  ;; XEmacs
   (defun TeX-completing-read-multiple
-    (prompt table &optional predicate require-match initial-input
-	    hist def inherit-input-method)
+      (prompt table &optional predicate require-match initial-input
+	      hist def inherit-input-method)
     "Poor mans implementation of Emacs' `completing-read-multiple' for XEmacs.
 The XEmacs package edit-utils-2.32 includes `crm.el'."
     (multi-prompt (if (boundp 'crm-separator) crm-separator ",") nil prompt