diff --git a/include/pdal/filters/HexBin.hpp b/include/pdal/filters/HexBin.hpp
index c522c4639b..29174cab7f 100644
--- a/include/pdal/filters/HexBin.hpp
+++ b/include/pdal/filters/HexBin.hpp
@@ -107,6 +107,10 @@ class PDAL_DLL IteratorBase
     boost::uint32_t m_sample_number;
     boost::int32_t m_density;
     double m_edge_size;
+
+private:
+    IteratorBase& operator=(IteratorBase const&);
+
     
 };
 
diff --git a/src/filters/HexBin.cpp b/src/filters/HexBin.cpp
index c5d07dc563..87c241340e 100644
--- a/src/filters/HexBin.cpp
+++ b/src/filters/HexBin.cpp
@@ -163,7 +163,15 @@ boost::uint32_t HexBin::readBufferImpl(PointBuffer& buffer)
             if (bDoSample)
             {
                 if (getStage().getNumPoints() < m_sample_size)
-                    m_sample_size = getStage().getNumPoints();
+                {
+                    if (getStage().getNumPoints() >= std::numeric_limits<boost::uint32_t>::max())
+                    {
+                        throw pdal_error("point count >= size of 32bit integer, set a sample size");
+                    }
+                            
+                    m_sample_size = static_cast<boost::uint32_t>(getStage().getNumPoints());
+                }
+                        
                 if ( m_sample_number < m_sample_size )
                 {
                     m_samples.push_back(hexer::Point(x,y));