diff --git a/AtlasGeometryCommon/GeoModelEnvelopes/src/ForDetEnvelopeTool.h b/AtlasGeometryCommon/GeoModelEnvelopes/src/ForDetEnvelopeTool.h
index a083d7e17da64f7b639c20a6898c1a66495691bf..eb1d2009dd280f7a25daa9edd8a7510cbc5e64d4 100755
--- a/AtlasGeometryCommon/GeoModelEnvelopes/src/ForDetEnvelopeTool.h
+++ b/AtlasGeometryCommon/GeoModelEnvelopes/src/ForDetEnvelopeTool.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2018 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef ForDetEnvelopeTool_h 
@@ -8,7 +8,7 @@
 #include "GeoModelUtilities/GeoModelTool.h"
 class ForDetEnvelopeManager;
 
-class ForDetEnvelopeTool : public GeoModelTool 
+class ForDetEnvelopeTool final : public GeoModelTool 
 {
  public:
 
diff --git a/InnerDetector/InDetDigitization/FastTRT_Digitization/src/TRTFastDigitizationTool.cxx b/InnerDetector/InDetDigitization/FastTRT_Digitization/src/TRTFastDigitizationTool.cxx
index 38913f15bc9ce534587bec497789da59283e92fa..cd88c2d970c4bbecb6f664dbbc739093d1d96b52 100644
--- a/InnerDetector/InDetDigitization/FastTRT_Digitization/src/TRTFastDigitizationTool.cxx
+++ b/InnerDetector/InDetDigitization/FastTRT_Digitization/src/TRTFastDigitizationTool.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -391,7 +391,7 @@ StatusCode TRTFastDigitizationTool::produceDriftCircles(const EventContext& ctx)
 
       if ( m_useTrtElectronPidTool ) {
 
-        double position = ( fabs(BEC) == 1 ? hitGlobalPosition.z() : hitGlobalPosition.perp() );
+        double position = ( std::abs(BEC) == 1 ? hitGlobalPosition.z() : hitGlobalPosition.perp() );
 
         double probability;
         if ( abs( particleEncoding ) == 11 && kineticEnergy > 5000. ) {  // electron
diff --git a/InnerDetector/InDetRecTools/InDetEtaDependentCuts/InDetEtaDependentCuts/InDetEtaDependentCutsSvc.h b/InnerDetector/InDetRecTools/InDetEtaDependentCuts/InDetEtaDependentCuts/InDetEtaDependentCutsSvc.h
index 11e8edb932bd8a6bf356057ba4bd25a422534e73..e85bf88234dff999180490098788a195b0677ffa 100644
--- a/InnerDetector/InDetRecTools/InDetEtaDependentCuts/InDetEtaDependentCuts/InDetEtaDependentCutsSvc.h
+++ b/InnerDetector/InDetRecTools/InDetEtaDependentCuts/InDetEtaDependentCuts/InDetEtaDependentCutsSvc.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 */
 #ifndef INDETETADEPENDENTCUTS_INDETETADEPENDENTCUTSSVC_H
 #define INDETETADEPENDENTCUTS_INDETETADEPENDENTCUTSSVC_H
@@ -18,9 +18,9 @@
 #include "GaudiKernel/ISvcLocator.h"
 
 namespace InDet {
-  class InDetEtaDependentCutsSvc: virtual public IInDetEtaDependentCutsSvc,
-                                  public AthService {
-
+  class InDetEtaDependentCutsSvc final
+    : virtual public IInDetEtaDependentCutsSvc, public AthService
+  {
     /////////////////////////////////////////////////////////////////// 
     // Public methods: 
     ///////////////////////////////////////////////////////////////////