diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index c812f28c1b..92c3d5c9d5 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -794,6 +794,11 @@ project-find-regexp
   (let* ((caller-dir default-directory)
          (pr (project-current t))
          (default-directory (project-root pr))
+         (xref-search-program
+          (if (and (eq xref-search-program 'ripgrep)
+                   (not (executable-find "rg" t)))
+              'grep
+              xref-search-program))
          (files
           (if (not current-prefix-arg)
               (project-files pr)