diff --git a/vm/TEST_MAPPING b/vm/TEST_MAPPING
index 485c3af..f1f48a6 100644
--- a/vm/TEST_MAPPING
+++ b/vm/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit": [
     {