diff --git a/src/window.c b/src/window.c
index 35ec2a1f908..ed30544ff83 100644
--- a/src/window.c
+++ b/src/window.c
@@ -8309,7 +8309,8 @@ on their symbols to be controlled by this variable.  */);
   Vscroll_preserve_screen_position = Qnil;
 
   DEFVAR_LISP ("window-point-insertion-type", Vwindow_point_insertion_type,
-	       doc: /* Type of marker to use for `window-point'.  */);
+	       doc: /* Insertion type of marker to use for `window-point'.
+See `marker-insertion-type' for the meaning of the possible values.  */);
   Vwindow_point_insertion_type = Qnil;
   DEFSYM (Qwindow_point_insertion_type, "window-point-insertion-type");