diff --git a/config.def.h b/config.def.h
index 8f498d2..a784eb4 100644
--- a/config.def.h
+++ b/config.def.h
@@ -36,6 +36,8 @@ static const Layout layouts[] = {
 };
 
 /* monitors */
+/* (x=-1, y=-1) is reserved as an "autoconfigure" monitor position indicator */
+/* WARNING: negative values other than (-1, -1) cause problems with xwayland clients' menus */
 /* NOTE: ALWAYS add a fallback rule, even if you are completely sure it won't be used */
 static const MonitorRule monrules[] = {
 	/* name       mfact  nmaster scale layout       rotate/reflect                x    y */
diff --git a/dwl.c b/dwl.c
index 52bfbc8..1ea7f2a 100644
--- a/dwl.c
+++ b/dwl.c
@@ -927,14 +927,14 @@ createmon(struct wl_listener *listener, void *data)
 	m->fullscreen_bg = wlr_scene_rect_create(layers[LyrFS], 0, 0, fullscreen_bg);
 	wlr_scene_node_set_enabled(&m->fullscreen_bg->node, 0);
 
-	/* Adds this to the output layout in the order it was configured in.
+	/* Adds this to the output layout in the order it was configured.
 	 *
 	 * The output layout utility automatically adds a wl_output global to the
 	 * display, which Wayland clients can see to find out information about the
 	 * output (such as DPI, scale factor, manufacturer, etc).
 	 */
 	m->scene_output = wlr_scene_output_create(scene, wlr_output);
-	if (m->m.x < 0 || m->m.y < 0)
+	if (m->m.x == -1 && m->m.y == -1)
 		wlr_output_layout_add_auto(output_layout, wlr_output);
 	else
 		wlr_output_layout_add(output_layout, wlr_output, m->m.x, m->m.y);