diff --git a/Rendering/OpenGL2/vtkOpenGLCellToVTKCellMap.cxx b/Rendering/OpenGL2/vtkOpenGLCellToVTKCellMap.cxx
index 11f29845eaf458faeccbc0bf8f3a2109a94a2171..66d7f8ea5efbc81d132074384713ef0079f27e43 100644
--- a/Rendering/OpenGL2/vtkOpenGLCellToVTKCellMap.cxx
+++ b/Rendering/OpenGL2/vtkOpenGLCellToVTKCellMap.cxx
@@ -29,6 +29,11 @@ vtkOpenGLCellToVTKCellMap::vtkOpenGLCellToVTKCellMap()
   this->PrimitiveOffsets[1] = 0;
   this->PrimitiveOffsets[2] = 0;
   this->PrimitiveOffsets[3] = 0;
+
+  this->CellMapSizes[0] = 0;
+  this->CellMapSizes[1] = 0;
+  this->CellMapSizes[2] = 0;
+  this->CellMapSizes[3] = 0;
 }
 
 // ----------------------------------------------------------------------------