diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index d35e88032..ce6a2b54b 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -34,6 +34,7 @@ class PaneAxisModel extends Model
 
   serializeParams: ->
     children: @children.map (child) -> child.serialize()
+    orientation: @orientation
 
   getViewClass: ->
     if @orientation is 'vertical'