diff --git a/Tracking/TrkExtrapolation/TrkExRungeKuttaIntersector/TrkExRungeKuttaIntersector/ATLAS_CHECK_THREAD_SAFETY b/Tracking/TrkExtrapolation/TrkExRungeKuttaIntersector/TrkExRungeKuttaIntersector/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..3f6f2cdcc271162f7b42abd4f3e2b1198ff216c5
--- /dev/null
+++ b/Tracking/TrkExtrapolation/TrkExRungeKuttaIntersector/TrkExRungeKuttaIntersector/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+Tracking/TrkExtrapolation/TrkExRungeKuttaIntersector
diff --git a/Tracking/TrkExtrapolation/TrkExSolenoidalIntersector/TrkExSolenoidalIntersector/ATLAS_CHECK_THREAD_SAFETY b/Tracking/TrkExtrapolation/TrkExSolenoidalIntersector/TrkExSolenoidalIntersector/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..a81518d524cd4bb5b5322d17d9a0294a72e41276
--- /dev/null
+++ b/Tracking/TrkExtrapolation/TrkExSolenoidalIntersector/TrkExSolenoidalIntersector/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+Tracking/TrkExtrapolation/TrkExSolenoidalIntersector
diff --git a/Tracking/TrkExtrapolation/TrkExStraightLineIntersector/TrkExStraightLineIntersector/ATLAS_CHECK_THREAD_SAFETY b/Tracking/TrkExtrapolation/TrkExStraightLineIntersector/TrkExStraightLineIntersector/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..8952a267747ae424b25a7e2e806612860af1cbbe
--- /dev/null
+++ b/Tracking/TrkExtrapolation/TrkExStraightLineIntersector/TrkExStraightLineIntersector/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+Tracking/TrkExtrapolation/TrkExStraightLineIntersector