When a DNS server replies an error other than NXDOMAIN, there is no mechanism to specify how long this error can be cached by the recepient. This document introduces a mechanism where a server can specify the time to live (TTL) of an error by adding a SOA record to the additional section of a reply. Clients can use this TTL at their discretion. In particular, clients can limit the TTL to a maximum value, impose a minimum value or just ignore the TTL value all together.