diff --git a/data/conf/rspamd/custom/bad_header.map b/data/conf/rspamd/custom/bad_header.map
index 33c9ee22..b053f545 100644
--- a/data/conf/rspamd/custom/bad_header.map
+++ b/data/conf/rspamd/custom/bad_header.map
@@ -1 +1 @@
-/Thread-Topic:\s[a-zA-Z]{3}\s[a-zA-Z]{2}\s*/i
+/Thread-Topic:\s[a-zA-Z]{3}\s[a-zA-Z]{2}[\s\r\n]{0,1}[^a-zA-Z0-9][\r\n]/i