diff --git a/FullSimLight/include/FSLDetectorConstruction.hh b/FullSimLight/include/FSLDetectorConstruction.hh
index 3eff8593fdcbc47c73a749e7ba1e567eed321f86..f470a69a23526168d0ca5f9eaba78ad1615c565c 100644
--- a/FullSimLight/include/FSLDetectorConstruction.hh
+++ b/FullSimLight/include/FSLDetectorConstruction.hh
@@ -1,4 +1,6 @@
-
+/*
+  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+*/
 #ifndef FSLDetectorConstruction_h
 #define FSLDetectorConstruction_h 1
 
diff --git a/FullSimLight/include/MassCalculator.hh b/FullSimLight/include/MassCalculator.hh
index 11d07b235edfe977ad18265a2bbfc2ea8d21bb1d..a713292d1c6980e63731eb2beba300ecde689e69 100644
--- a/FullSimLight/include/MassCalculator.hh
+++ b/FullSimLight/include/MassCalculator.hh
@@ -1,3 +1,7 @@
+/*
+  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+*/
+
 #ifndef MassCalculator_h
 #define MassCalculator_h 1
 
diff --git a/FullSimLight/src/FSLDetectorConstruction.cc b/FullSimLight/src/FSLDetectorConstruction.cc
index b835b761c04a6d0ab3249c170871cc12252f9598..d4b5e535ae7ddfe41c4c847cc6c0fdcb35591a85 100644
--- a/FullSimLight/src/FSLDetectorConstruction.cc
+++ b/FullSimLight/src/FSLDetectorConstruction.cc
@@ -1,3 +1,7 @@
+/*
+  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+*/
+
 #include "FSLDetectorConstruction.hh"
 #include "FSLDetectorMessenger.hh"
 #include "RegionConfigurator.hh"
diff --git a/FullSimLight/src/MassCalculator.cc b/FullSimLight/src/MassCalculator.cc
index edf495781f7de132f9c5349e097ac7b6c726aac0..cb103e1a366b2c24cd0a64c95d43aa841cb2af5a 100644
--- a/FullSimLight/src/MassCalculator.cc
+++ b/FullSimLight/src/MassCalculator.cc
@@ -1,3 +1,7 @@
+/*
+  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+*/
+
 #include "MassCalculator.hh"
 #include "GeoModelKernel/GeoVolumeCursor.h"