diff --git a/Event/xAOD/xAODHIEvent/xAODHIEvent/ATLAS_CHECK_THREAD_SAFETY b/Event/xAOD/xAODHIEvent/xAODHIEvent/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..17c801c274d95123d8e26c21fb9f9377f7c24e69
--- /dev/null
+++ b/Event/xAOD/xAODHIEvent/xAODHIEvent/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+Event/xAOD/xAODHIEvent