diff --git a/Framework/DataHandling/inc/MantidDataHandling/LoadILLTOF2.h b/Framework/DataHandling/inc/MantidDataHandling/LoadILLTOF2.h
index ca7c8b2f328ed1e4df75dcd6f9878e4a9c812ea7..30ad9480441c387a90d401036465d13770d2b027 100644
--- a/Framework/DataHandling/inc/MantidDataHandling/LoadILLTOF2.h
+++ b/Framework/DataHandling/inc/MantidDataHandling/LoadILLTOF2.h
@@ -74,7 +74,7 @@ private:
                                 const std::vector<std::vector<int>> &);
   void loadSpectra(size_t &spec, const size_t numberOfTubes,
                    const std::vector<Mantid::detid_t> &detectorIDs,
-                   NeXus::NXInt data, Mantid::API::Progress progress);
+                   const NeXus::NXInt &data, Mantid::API::Progress &progress);
 
   void runLoadInstrument();
 
diff --git a/Framework/DataHandling/src/LoadILLTOF2.cpp b/Framework/DataHandling/src/LoadILLTOF2.cpp
index 0ae774efd2026c43b9ad8b036b8b0741e8d55ec2..5ff8014cd7b65713faefffdae252011d216ecb20 100644
--- a/Framework/DataHandling/src/LoadILLTOF2.cpp
+++ b/Framework/DataHandling/src/LoadILLTOF2.cpp
@@ -404,7 +404,7 @@ void LoadILLTOF2::loadDataIntoTheWorkSpace(
  */
 void LoadILLTOF2::loadSpectra(size_t &spec, const size_t numberOfTubes,
                               const std::vector<detid_t> &detectorIDs,
-                              NXInt data, Progress progress) {
+                              const NXInt &data, Progress &progress) {
   for (size_t i = 0; i < numberOfTubes; ++i) {
     for (size_t j = 0; j < m_numberOfPixelsPerTube; ++j) {
       int *data_p = &data(static_cast<int>(i), static_cast<int>(j), 0);