diff --git a/TODO.markdown b/TODO.markdown
index 46b362a1..3bb950fb 100644
--- a/TODO.markdown
+++ b/TODO.markdown
@@ -17,6 +17,11 @@ things that need to be fixed.
 
 ## BUGS
 
+* ListenAndServe has trouble with v6:
+    Failed to setup the udp6 server: listen udp6 <nil>:8053: address already in use
+    Failed to setup the tcp6 server: listen tcp6 <nil>:8053: address already in use
+
+
 ## Examples to add
 
 * Nameserver, with a small zone, 1 KSK and online signing;