diff --git a/Packages/vcs/Lib/VTKPlots.py b/Packages/vcs/Lib/VTKPlots.py
index e98d59ea79..b4dc59de0e 100644
--- a/Packages/vcs/Lib/VTKPlots.py
+++ b/Packages/vcs/Lib/VTKPlots.py
@@ -47,7 +47,7 @@ def __init__(self,canvas,renWin=None, debug=False,bg=None):
     self.logoRepresentation = None
     self.renderer = None
     self._renderers = {}
-    self._plot_keywords = ['renderer','vtk_backend_grid','vtk_backend_geo']
+    self._plot_keywords = [ 'renderer','vtk_backend_grid','vtk_backend_geo', 'cdmsfile', 'cell_coordinates' ]
     self.numberOfPlotCalls = 0
     self.renderWindowSize=None