   open: =>
     if @canTransitionIn()
       @_setElementClasses 'opening'
-      @transitionIn().then => @_setElementClasses 'open'
+      @_setupDrawer().then =>
+        @transitionIn().then => @_setElementClasses 'open'
     else
       Promise.rejected()
 

    else
      @container.classList.remove DRAWER_CONTAINER_CLS
      @viewport.classList.remove DRAWER_VIEWPORT_CLS


  ###*

    # Set the pane transition type.
    if @behavior is 'push'
      @transition = 'fade'
      p = @getRenderedDimensions().then (d) =>
        @root.style.left = -d.width + 'px'
    else
      @transition = 'overlay'
