diff --git a/Event/EventInfo/src/EventStreamInfo.cxx b/Event/EventInfo/src/EventStreamInfo.cxx
index 3bab00431379d9e73be764e9933da2a3374ecd9c..99842d84c92e7fc07beba0ffbbef373db01f0a63 100644
--- a/Event/EventInfo/src/EventStreamInfo.cxx
+++ b/Event/EventInfo/src/EventStreamInfo.cxx
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+   Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
  */
 
 /** @file EventStreamInfo.cxx
@@ -99,7 +99,7 @@ EventStreamInfo::print(MsgStream& log) const {
   }
   log << MSG::DEBUG << endmsg;
   log << MSG::DEBUG << "EventStreamInfo Processing Tags: ";
-  for (const std::string tag : m_processingTags) {
+  for (const std::string& tag : m_processingTags) {
     log << MSG::DEBUG << tag << ", ";
   }
   log << MSG::DEBUG << endmsg;
diff --git a/Event/xAOD/xAODTau/Root/TauJet_v3.cxx b/Event/xAOD/xAODTau/Root/TauJet_v3.cxx
index a465a61feee2a16cc3dd2575b592ff50d80f2b69..2f62bb0434de302004263ba69cc88f8253da477e 100644
--- a/Event/xAOD/xAODTau/Root/TauJet_v3.cxx
+++ b/Event/xAOD/xAODTau/Root/TauJet_v3.cxx
@@ -537,7 +537,7 @@ namespace xAOD {
   /// Get the v<const pointer> to a given tauTrack collection associated with this tau
   std::vector<const TauTrack*> TauJet_v3::tracksWithMask(unsigned int mask )const {
   std::vector<const TauTrack*> trks;
-    for(const ElementLink< xAOD::TauTrackContainer > link : tauTrackAcc(*this) ){
+    for(const ElementLink< xAOD::TauTrackContainer >& link : tauTrackAcc(*this) ){
       const TauTrack* trk = *link;
       if(trk->flagWithMask(mask)){
 	trks.push_back(trk);
diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/MM_RawDataContainerCnv_p1.cxx b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/MM_RawDataContainerCnv_p1.cxx
index d9bab01dc75b9e7fbb05736166f3ce467037ac6e..dfc96281ecd053ce5259acd4d65b1e4a61ba860c 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/MM_RawDataContainerCnv_p1.cxx
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/MM_RawDataContainerCnv_p1.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "MuonEventTPCnv/MuonRDO/MM_RawDataContainerCnv_p1.h"
@@ -40,7 +40,7 @@ void  Muon::MM_RawDataContainerCnv_p1::persToTrans(const Muon::MM_RawDataContain
   if (DEBUG) log<<MSG::VERBOSE<<"MM_RawDataContainerCnv_p1::persToTrans with MM_RawDataContainer_p1 with this many collections "<<numColl<<std::endl;
     
   MM_RawDataCollection* coll = nullptr;
-  for ( const MM_RawDataCollection_p1 collection : *persCont){
+  for ( const MM_RawDataCollection_p1& collection : *persCont){
 
     coll = new MM_RawDataCollection(collection.m_idHash);
     if ( transCont->addCollection(coll,collection.m_idHash).isFailure() ) {
diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/STGC_RawDataContainerCnv_p1.cxx b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/STGC_RawDataContainerCnv_p1.cxx
index ece37a850d4f8056067d99163ceb83c21c47e545..6c0e4080ed6ac73ca04d98f393b2cc8925740761 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/STGC_RawDataContainerCnv_p1.cxx
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonRDO/STGC_RawDataContainerCnv_p1.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "MuonEventTPCnv/MuonRDO/STGC_RawDataContainerCnv_p1.h"
@@ -39,7 +39,7 @@ void  Muon::STGC_RawDataContainerCnv_p1::persToTrans(const Muon::STGC_RawDataCon
   if (DEBUG) log<<MSG::VERBOSE<<"STGC_RawDataContainerCnv_p1::persToTrans with STGC_RawDataContainer_p1 with this many collections "<<numColl<<std::endl;
     
   STGC_RawDataCollection* coll = nullptr;
-  for ( const STGC_RawDataCollection_p1 collection : *persCont){
+  for ( const STGC_RawDataCollection_p1& collection : *persCont){
     coll = new STGC_RawDataCollection(collection.m_idHash);
     if ( transCont->addCollection(coll,collection.m_idHash).isFailure() ) {
       log << MSG::WARNING << "Could not add the sTGC collection during persistent->transient conversion" << std::endl;
diff --git a/Trigger/TrigConfiguration/TrigConfIO/utils/TriggerMenuRW.cxx b/Trigger/TrigConfiguration/TrigConfIO/utils/TriggerMenuRW.cxx
index c430147f5feed60588ce9cbee1046169e5a318ef..a7a80c4e96de03b2e8945ae4cffa1619e3ed126a 100644
--- a/Trigger/TrigConfiguration/TrigConfIO/utils/TriggerMenuRW.cxx
+++ b/Trigger/TrigConfiguration/TrigConfIO/utils/TriggerMenuRW.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include <cstdlib>
@@ -245,9 +245,9 @@ int main(int argc, char** argv) {
             fileLoader.loadFile( fn, jo);
             cout << "Loaded job options with " << jo.getObject("properties").getKeys().size() << " entries " << endl;
             if( cfg.detail ) {
-               for( const auto alg : jo.getObject("properties").data()) {
+               for( const auto& alg : jo.getObject("properties").data()) {
                   std::cout << alg.first << std::endl;
-                  for( const auto prop : alg.second ) {
+                  for( const auto& prop : alg.second ) {
                      std::cout << "      " << prop.first << " -> " << prop.second.data() << std::endl;
                   }
                }
@@ -292,9 +292,9 @@ int main(int argc, char** argv) {
       if (jo) {
          cout << "Loaded job options with " << jo.getObject("properties").getKeys().size() << " entries " << endl;
          if( cfg.detail ) {
-            for( const auto alg : jo.getObject("properties").data()) {
+            for( const auto& alg : jo.getObject("properties").data()) {
                std::cout << alg.first << std::endl;
-               for( const auto prop : alg.second ) {
+               for( const auto& prop : alg.second ) {
                   std::cout << "      " << prop.first << " -> " << prop.second.data() << std::endl;
                }
             }