diff --git a/data/conf/rspamd/custom/bad_header.map b/data/conf/rspamd/custom/bad_header.map
new file mode 100644
index 00000000..33c9ee22
--- /dev/null
+++ b/data/conf/rspamd/custom/bad_header.map
@@ -0,0 +1 @@
+/Thread-Topic:\s[a-zA-Z]{3}\s[a-zA-Z]{2}\s*/i