diff --git a/VTK/Filtering/vtkPolyData.cxx b/VTK/Filtering/vtkPolyData.cxx
index 5b1675e..1ec6426 100644
--- a/VTK/Filtering/vtkPolyData.cxx
+++ b/VTK/Filtering/vtkPolyData.cxx
@@ -33,6 +33,8 @@
 #include "vtkTriangleStrip.h"
 #include "vtkVertex.h"
 
+#include <stdexcept>
+
 vtkStandardNewMacro(vtkPolyData);
 
 //----------------------------------------------------------------------------
@@ -1001,10 +1003,14 @@ void vtkPolyData::BuildCells()
       {
       cells->InsertNextCell(VTK_POLY_LINE,inLines->GetTraversalLocation(npts));
       }
-    else
+    else if (npts == 2)
       {
       cells->InsertNextCell(VTK_LINE,inLines->GetTraversalLocation(npts));
       } 
+    else
+      {
+      throw std::logic_error("PLEASE REPORT: 1-point line found that should be culled");
+      }
     }
 
   for (inPolys->InitTraversal(); inPolys->GetNextCell(npts,pts); )