diff --git a/defaults.go b/defaults.go
index 1f487b14..7aa1b0ca 100644
--- a/defaults.go
+++ b/defaults.go
@@ -42,7 +42,7 @@ func (dns *Msg) SetRcode(request *Msg, rcode int) {
         dns.Question[0] = request.Question[0]
 }
 
-// IsRocde checks if the header of the packet has rcode set.
+// IsRcode checks if the header of the packet has rcode set.
 func (dns *Msg) IsRcode(rcode int) (ok bool) {
 	if len(dns.Question) == 0 {
 		return false
@@ -69,7 +69,7 @@ func (dns *Msg) IsRcodeFormatError() (ok bool) {
         return
 }
 
-// Is the message a dynamic update packet?
+// IsUpdate checks if the message is a dynamic update packet?
 func (dns *Msg) IsUpdate() (ok bool) {
 	if len(dns.Question) == 0 {
 		return false
@@ -79,6 +79,14 @@ func (dns *Msg) IsUpdate() (ok bool) {
 	return
 }
 
+// SetUpdate makes the message a dynamic update packet. It
+// sets the ZONE section to: z, TypeSOA, classINET.
+func (dns *Msg) SetUpdate(z string) {
+        dns.MsgHdr.Opcode = OpcodeUpdate
+	dns.Question = make([]Question, 1)
+	dns.Question[0] = Question{z, TypeSOA, ClassINET}
+}
+
 // Is the message a valid notify packet?
 func (dns *Msg) IsNotify() (ok bool) {
 	if len(dns.Question) == 0 {