     (@paneContainer.getPanes().length > 1) or (@pane.getItems().length > 1)
 
   onDragStart: (event) =>
+    return unless event.target.classList.contains('sortable')
+
     event.originalEvent.dataTransfer.setData 'atom-event', 'true'
 
     element = $(event.target).closest('.sortable')

    @removePlaceholder()

  onDragEnd: (event) =>
    @clearDropTarget()

  onDragOver: (event) =>

      'tabs:split-left': => @splitTab('splitLeft')
      'tabs:split-right': => @splitTab('splitRight')

    @element.addEventListener "dragstart", @onDragStart
    @element.addEventListener "dragend", @onDragEnd
    @element.addEventListener "dragleave", @onDragLeave
    @element.addEventListener "dragover", @onDragOver
    @element.addEventListener "drop", @onDrop

    @paneContainer = @pane.getContainer()
    @addTabForItem(item) for item in @pane.getItems()
