diff --git a/IO/MPIImage/vtkPNrrdReader.cxx b/IO/MPIImage/vtkPNrrdReader.cxx
index f9c4d879abf5e1a13c248a7fe824bc30f0fe776c..a78a9da7f374392796148ade8959efd3b6e89143 100644
--- a/IO/MPIImage/vtkPNrrdReader.cxx
+++ b/IO/MPIImage/vtkPNrrdReader.cxx
@@ -26,6 +26,7 @@
 #include "vtkObjectFactory.h"
 #include "vtkStringArray.h"
 
+#include <algorithm>
 #include <string>
 #include <vector>
 #include <vtksys/SystemTools.hxx>
@@ -308,16 +309,25 @@ void vtkPNrrdReader::ReadSlice(int slice, const int extent[6], void *buffer)
   length *= extent[3]-extent[2]+1;
   if (this->GetFileDimensionality() == 3) length *= extent[5]-extent[4]+1;
 
-  if (length > VTK_INT_MAX)
+  vtkIdType pos = 0;
+  while (length > pos)
     {
-    vtkErrorMacro(<< "Cannot read more than " << VTK_INT_MAX
-                  << " bytes at a time.");
+    MPI_Status stat;
+    // we know this will fit in an int because it can't exceed VTK_INT_MAX.
+    const int remaining = std::min(static_cast<size_t>(length - pos),
+                                   static_cast<size_t>(VTK_INT_MAX));
+    MPICall(MPI_File_read(file.Handle, (static_cast<char*>(buffer)) + pos, remaining,
+                          MPI_BYTE, &stat));
+    int rd = 0;
+    MPICall(MPI_Get_elements(&stat, MPI_BYTE, &rd));
+    if (MPI_UNDEFINED == rd)
+      {
+      vtkErrorMacro("Error obtaining number of values read in " << remaining <<
+                    "-byte read.");
+      }
+    pos += static_cast<vtkIdType>(rd);
     }
 
-  // Do the read.  This is a coordinated parallel operation for efficiency.
-  MPICall(MPI_File_read_all(file.Handle, buffer, static_cast<int>(length),
-                            MPI_BYTE, MPI_STATUS_IGNORE));
-
   MPICall(MPI_File_close(&file.Handle));
 }
 #else // VTK_USE_MPI_IO