diff --git a/Alignment/MillePedeAlignmentAlgorithm/plugins/RunRangeDependentPedeLabeler.cc b/Alignment/MillePedeAlignmentAlgorithm/plugins/RunRangeDependentPedeLabeler.cc
index b2a5a2bab8001..c1e34ca4419f0 100644
--- a/Alignment/MillePedeAlignmentAlgorithm/plugins/RunRangeDependentPedeLabeler.cc
+++ b/Alignment/MillePedeAlignmentAlgorithm/plugins/RunRangeDependentPedeLabeler.cc
@@ -191,7 +191,7 @@ unsigned int RunRangeDependentPedeLabeler::numberOfParameterInstances(Alignable*
   if (positionAli != theAlignableToRunRangeRangeMap.end()) {
     size_t nRunRanges = 1;
     if (param == -1) {
-      for (const auto iParam : (*positionAli).second) {
+      for (const auto& iParam : (*positionAli).second) {
         nRunRanges = std::max(nRunRanges, iParam.second.size());
       }
       return nRunRanges;