diff --git a/tools/ubsan/ignorelist.txt b/tools/ubsan/ignorelist.txt
index 7a2271d..e140fc5 100644
--- a/tools/ubsan/ignorelist.txt
+++ b/tools/ubsan/ignorelist.txt
@@ -1,3 +1,6 @@
+#!special-case-list-v1
+# TODO(https://crbug.com/1515966): update to glob patterns
+
 #############################################################################
 # UBSan ignore list.
 
diff --git a/tools/ubsan/security_ignorelist.txt b/tools/ubsan/security_ignorelist.txt
index 30f66a4..df60337 100644
--- a/tools/ubsan/security_ignorelist.txt
+++ b/tools/ubsan/security_ignorelist.txt
@@ -1,3 +1,6 @@
+#!special-case-list-v1
+# TODO(https://crbug.com/1515966): update to glob patterns
+
 # This ignore  list is a merge of ignorelist.txt and vptr_ignorelist.txt.
 
 #############################################################################