diff --git a/lib/hx509/TODO b/lib/hx509/TODO
index daa2234e4..d83166eed 100644
--- a/lib/hx509/TODO
+++ b/lib/hx509/TODO
@@ -9,6 +9,8 @@ DSA2 support
 
 x509 policy mappings support
 
+CRL delta support
+
 crypto
 	make signing alg depend on signer if not given