diff --git a/LArCalorimeter/LArRawUtils/CMakeLists.txt b/LArCalorimeter/LArRawUtils/CMakeLists.txt
index 1eacf72f7c56f243264910aa1a45585581ef59c8..7bcf7e2e66b255dd1657992a31416beb61961248 100644
--- a/LArCalorimeter/LArRawUtils/CMakeLists.txt
+++ b/LArCalorimeter/LArRawUtils/CMakeLists.txt
@@ -7,7 +7,7 @@ atlas_subdir( LArRawUtils )
 atlas_add_library( LArRawUtilsLib
                    src/*.cxx
                    PUBLIC_HEADERS LArRawUtils
-                   LINK_LIBRARIES CaloIdentifier CaloTTDetDescr AthenaBaseComps AthenaKernel Identifier GaudiKernel LArCablingLib LArIdentifier LArRawEvent StoreGateLib CaloTriggerToolLib
+                   LINK_LIBRARIES CaloIdentifier CaloTTDetDescr AthenaBaseComps AthenaKernel Identifier GaudiKernel LArCablingLib LArIdentifier LArRawEvent StoreGateLib CaloTriggerToolLib CxxUtils
                    PRIVATE_LINK_LIBRARIES AtlasDetDescr )
 
 atlas_add_component( LArRawUtils
diff --git a/LArCalorimeter/LArRawUtils/LArRawUtils/ATLAS_CHECK_THREAD_SAFETY b/LArCalorimeter/LArRawUtils/LArRawUtils/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..b64f7f52b5127e2eaa002647ff004325133c9b08
--- /dev/null
+++ b/LArCalorimeter/LArRawUtils/LArRawUtils/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+LArCalorimeter/LArRawUtils
diff --git a/LArCalorimeter/LArRawUtils/LArRawUtils/LArRawOrdering.h b/LArCalorimeter/LArRawUtils/LArRawUtils/LArRawOrdering.h
index 68ce79f0b7ab6910688140d49e1861df583d4b4e..6f6f5e62394e43559031cb66226058be4aa98527 100755
--- a/LArCalorimeter/LArRawUtils/LArRawUtils/LArRawOrdering.h
+++ b/LArCalorimeter/LArRawUtils/LArRawUtils/LArRawOrdering.h
@@ -1,17 +1,18 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef LARRAWUTILS_LARRAWORDERING_H
 #define LARRAWUTILS_LARRAWORDERING_H
 
 
-#include "LArRawEvent/LArRawChannel.h" 
+#include "LArRawEvent/LArRawChannel.h"
+#include "CxxUtils/checker_macros.h"
 
 class LArRoI_Map; 
 
 
-class LArRawOrdering
+class ATLAS_NOT_THREAD_SAFE LArRawOrdering
 {
 
   public: 
diff --git a/LArCalorimeter/LArRawUtils/LArRawUtils/LArRoI_Map.h b/LArCalorimeter/LArRawUtils/LArRawUtils/LArRoI_Map.h
index 4d1c4aff52990d63047b8a5889b317f44b77919b..4e5b383741dd5e964b494a695b412f3fb56f2696 100644
--- a/LArCalorimeter/LArRawUtils/LArRawUtils/LArRoI_Map.h
+++ b/LArCalorimeter/LArRawUtils/LArRawUtils/LArRoI_Map.h
@@ -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
 */
 
 #ifndef LARRAWEVENT_LARROI_MAP_H
@@ -16,6 +16,7 @@
 #include "StoreGate/DataHandle.h" 
 #include "GaudiKernel/IIncidentListener.h"
 #include "AthenaKernel/IOVSvcDefs.h"
+#include "CxxUtils/checker_macros.h"
 
 #include "AthenaBaseComps/AthAlgTool.h"
 #include <map> 
@@ -36,8 +37,10 @@ class LArFCAL_ID ;
  */
 
 
-class LArRoI_Map : public AthAlgTool,
-		      public IIncidentListener 
+// Not thread-safe due to the use of old cabling tools + callbacks
+class ATLAS_NOT_THREAD_SAFE
+      LArRoI_Map : public AthAlgTool,
+                   public IIncidentListener 
  { 
 
  public:
diff --git a/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.h b/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.h
index 05701fea0b063eee6b0d8bb42d9fb72a5aea6c7d..4f82517311334524d0e89fcc1a6c6f3508bd1d71 100755
--- a/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.h
+++ b/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.h
@@ -1,15 +1,17 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef LARRAWUTILS_LARTT_SELECTOR_H
 #define LARRAWUTILS_LARTT_SELECTOR_H
 
 #include "Identifier/Identifier.h" 
-#include "Identifier/IdentifierHash.h" 
+#include "Identifier/IdentifierHash.h"
+#include "CxxUtils/checker_macros.h"
 
 class LArRoI_Map; 
 
+// Not thread-safe due to the use of LArRoI_Map.
 template <class CONTAINER >
 class LArTT_Selector
 {
@@ -95,7 +97,8 @@ class LArTT_Selector
 
    // set RoI according TT, + a sam number. 
 //   void setRoIs( const VEC_TT_ID& ids,  int sam ) ; 
-   void setRoIs( const VEC_TT_ID& ids ) ; 
+   // Not thread-safe due to the use of LArRoI_Map.
+   void setRoIs ATLAS_NOT_THREAD_SAFE ( const VEC_TT_ID& ids ) ; 
 
    // set RoI according to combined TT_Sampling ID (unsigned int).    
 //   void setRoIs( const VEC_TT_SAM_ID& ids ) ; 
diff --git a/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.icc b/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.icc
index 88e6da0f02905d64e5c137a723403c72fd20cf34..d4bf18ecd92bf754d2911dbf81b3aec0f25bbd1b 100755
--- a/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.icc
+++ b/LArCalorimeter/LArRawUtils/LArRawUtils/LArTT_Selector.icc
@@ -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 "LArRawUtils/LArRoI_Map.h" 
@@ -150,7 +150,7 @@ void LArTT_Selector<CONTAINER>::setContainer(const CONTAINER* c) {
 template <class CONTAINER >
 //void LArTT_Selector<CONTAINER> :: setRoIs( const VEC_TT_ID& ids, 
 //							int sam)
-void LArTT_Selector<CONTAINER> :: setRoIs( const VEC_TT_ID& ids)
+void LArTT_Selector<CONTAINER> :: setRoIs ATLAS_NOT_THREAD_SAFE ( const VEC_TT_ID& ids)
 {
 
   // clean it up.