diff --git a/qt/widgets/instrumentview/src/MaskBinsData.cpp b/qt/widgets/instrumentview/src/MaskBinsData.cpp
index 5c49f576ed9c5aa1940de1d24a1390c9b842b767..54a849f8ad2f19d6a5a1a272ee4f45bc8df77200 100644
--- a/qt/widgets/instrumentview/src/MaskBinsData.cpp
+++ b/qt/widgets/instrumentview/src/MaskBinsData.cpp
@@ -21,14 +21,14 @@ void MaskBinsData::addXRange(double start, double end,
 void MaskBinsData::mask(const std::string &wsName) const {
   for (auto mask = m_masks.begin(); mask != m_masks.end(); ++mask) {
     auto &spectra = mask->spectra;
-    std::vector<int> spectraList(spectra.size());
+    std::vector<int64_t> spectraList(spectra.size());
     std::transform(spectra.cbegin(), spectra.cend(), spectraList.begin(),
                    [](const size_t spec)
                        -> int { return static_cast<int>(spec); });
     auto alg = Mantid::API::AlgorithmManager::Instance().create("MaskBins", -1);
     alg->setPropertyValue("InputWorkspace", wsName);
     alg->setPropertyValue("OutputWorkspace", wsName);
-    alg->setProperty("SpectraList", spectraList);
+    alg->setProperty("InputWorkspaceIndexSet", spectraList);
     alg->setProperty("XMin", mask->start);
     alg->setProperty("XMax", mask->end);
     alg->execute();