diff --git a/src/st/st-box-layout.c b/src/st/st-box-layout.c
index 8885f6a93..90c7d71f6 100644
--- a/src/st/st-box-layout.c
+++ b/src/st/st-box-layout.c
@@ -260,6 +260,8 @@ st_box_container_add_actor (ClutterContainer *container,
 
   priv->children = g_list_append (priv->children, actor);
 
+  clutter_actor_queue_relayout (CLUTTER_ACTOR (container));
+
   g_signal_emit_by_name (container, "actor-added", actor);
 }