diff --git a/etc/apps/paraview3/cshrc b/etc/apps/paraview3/cshrc
index 1659021664..aa9f8d3c56 100644
--- a/etc/apps/paraview3/cshrc
+++ b/etc/apps/paraview3/cshrc
@@ -48,7 +48,11 @@ setenv ParaView_VERSION 3
 setenv ParaView_INST_DIR $WM_PROJECT_INST_DIR/ParaView3.2.1
 setenv ParaView_DIR $ParaView_INST_DIR/platforms/$WM_OPTIONS
 
-setenv PYTHONPATH $PYTHONPATH:$ParaView_DIR/bin:$ParaView_DIR/Utilities/VTKPythonWrapping
+if ($?PYTHONPATH) then
+    setenv PYTHONPATH ${PYTHONPATH}:$ParaView_DIR/bin:$ParaView_DIR/Utilities/VTKPythonWrapping
+else
+    setenv PYTHONPATH $ParaView_DIR/bin:$ParaView_DIR/Utilities/VTKPythonWrapping
+endif
 
 if ( -r $ParaView_INST_DIR ) then
     set path=($ParaView_DIR/bin $path)