diff --git a/LArCalorimeter/LArG4/LArG4ShowerLib/LArG4ShowerLib/ATLAS_CHECK_THREAD_SAFETY b/LArCalorimeter/LArG4/LArG4ShowerLib/LArG4ShowerLib/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..66fae77bdb12a425039601b1cbdabb3d6ba60b1c
--- /dev/null
+++ b/LArCalorimeter/LArG4/LArG4ShowerLib/LArG4ShowerLib/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+LArCalorimeter/LArG4/LArG4ShowerLib
diff --git a/LArCalorimeter/LArG4/LArG4ShowerLibSvc/LArG4ShowerLibSvc/ATLAS_CHECK_THREAD_SAFETY b/LArCalorimeter/LArG4/LArG4ShowerLibSvc/LArG4ShowerLibSvc/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..b3cec4360709bacbb4f1de31e854f69eac93922c
--- /dev/null
+++ b/LArCalorimeter/LArG4/LArG4ShowerLibSvc/LArG4ShowerLibSvc/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+LArCalorimeter/LArG4/LArG4ShowerLibSvc/LArG4ShowerLibSvc