diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index 398339ee590..40d7e03baf4 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -213,6 +213,7 @@ DIRS must contain directory names."
 (declare-function grep-read-files "grep")
 (declare-function xref-collect-matches "xref")
 (declare-function xref--show-xrefs "xref")
+(declare-function xref-backend-identifier-at-point "xref")
 
 ;;;###autoload
 (defun project-find-regexp (regexp)
@@ -240,10 +241,8 @@ pattern to search for."
     (project--find-regexp-in dirs regexp pr)))
 
 (defun project--read-regexp ()
-  (defvar xref-identifier-at-point-function)
-  (require 'xref)
   (read-regexp "Find regexp"
-               (funcall xref-identifier-at-point-function)))
+               (xref-backend-identifier-at-point (xref-find-backend))))
 
 (defun project--find-regexp-in (dirs regexp project)
   (require 'grep)
diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 7e3b5600f1a..40f8d23c64a 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -210,6 +210,7 @@ and should return either nil to mean that it is not applicable,
 or an xref backend, which is a value to be used to dispatch the
 generic functions.")
 
+;;;###autoload
 (defun xref-find-backend ()
   (run-hook-with-args-until-success 'xref-backend-functions))