diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 6e8a108b506..496deb5c4f1 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -526,7 +526,8 @@ FILE is the file where FUNCTION was probably defined."
 	 (sig-key (if (subrp def)
                       (indirect-function real-def)
                     real-def))
-	 (file-name (find-lisp-object-file-name function def))
+	 (file-name (find-lisp-object-file-name function (if aliased 'defun
+                                                           def)))
          (pt1 (with-current-buffer (help-buffer) (point)))
 	 (beg (if (and (or (byte-code-function-p def)
 			   (keymapp def)