diff --git a/internal/dhcp6/dhcp6.go b/internal/dhcp6/dhcp6.go
index 0795aa1..7a52537 100644
--- a/internal/dhcp6/dhcp6.go
+++ b/internal/dhcp6/dhcp6.go
@@ -62,7 +62,7 @@ type Client struct {
 	raddr         *net.UDPAddr
 	timeNow       func() time.Time
 	duid          *dhcpv6.Duid
-	advertise     dhcpv6.DHCPv6
+	advertise     *dhcpv6.Message
 
 	cfg Config
 	err error
@@ -159,7 +159,7 @@ func (c *Client) Close() error {
 
 const maxUDPReceivedPacketSize = 8192 // arbitrary size. Theoretically could be up to 65kb
 
-func (c *Client) sendReceive(packet dhcpv6.DHCPv6, expectedType dhcpv6.MessageType) (dhcpv6.DHCPv6, error) {
+func (c *Client) sendReceive(packet *dhcpv6.Message, expectedType dhcpv6.MessageType) (*dhcpv6.Message, error) {
 	if packet == nil {
 		return nil, fmt.Errorf("Packet to send cannot be nil")
 	}
@@ -185,46 +185,36 @@ func (c *Client) sendReceive(packet dhcpv6.DHCPv6, expectedType dhcpv6.MessageTy
 	// wait for a reply
 	c.Conn.SetReadDeadline(time.Now().Add(c.ReadTimeout))
 	var (
-		adv       dhcpv6.DHCPv6
-		isMessage bool
+		adv *dhcpv6.Message
 	)
-	msg, ok := packet.(*dhcpv6.DHCPv6Message)
-	if ok {
-		isMessage = true
-	}
 	for {
 		buf := make([]byte, maxUDPReceivedPacketSize)
 		n, _, err := c.Conn.ReadFrom(buf)
 		if err != nil {
 			return nil, err
 		}
-		adv, err = dhcpv6.FromBytes(buf[:n])
+		adv, err = dhcpv6.MessageFromBytes(buf[:n])
 		if err != nil {
 			log.Printf("non-DHCP: %v", err)
 			// skip non-DHCP packets
 			continue
 		}
-		if recvMsg, ok := adv.(*dhcpv6.DHCPv6Message); ok && isMessage {
-			// if a regular message, check the transaction ID first
-			// XXX should this unpack relay messages and check the XID of the
-			// inner packet too?
-			if msg.TransactionID() != recvMsg.TransactionID() {
-				log.Printf("different XID: got %v, want %v", recvMsg.TransactionID(), msg.TransactionID())
-				// different XID, we don't want this packet for sure
-				continue
-			}
+		if packet.TransactionID != adv.TransactionID {
+			log.Printf("different XID: got %v, want %v", adv.TransactionID, packet.TransactionID)
+			// different XID, we don't want this packet for sure
+			continue
 		}
 		if expectedType == dhcpv6.MessageTypeNone {
 			// just take whatever arrived
 			break
-		} else if adv.Type() == expectedType {
+		} else if adv.MessageType == expectedType {
 			break
 		}
 	}
 	return adv, nil
 }
 
-func (c *Client) solicit(solicit dhcpv6.DHCPv6) (dhcpv6.DHCPv6, dhcpv6.DHCPv6, error) {
+func (c *Client) solicit(solicit *dhcpv6.Message) (*dhcpv6.Message, *dhcpv6.Message, error) {
 	var err error
 	if solicit == nil {
 		solicit, err = dhcpv6.NewSolicitForInterface(c.interfaceName, dhcpv6.WithClientID(*c.duid))
@@ -235,7 +225,7 @@ func (c *Client) solicit(solicit dhcpv6.DHCPv6) (dhcpv6.DHCPv6, dhcpv6.DHCPv6, e
 	if len(c.transactionIDs) > 0 {
 		id := c.transactionIDs[0]
 		c.transactionIDs = c.transactionIDs[1:]
-		solicit.(*dhcpv6.DHCPv6Message).SetTransactionID(id)
+		solicit.TransactionID = id
 	}
 	iapd := []byte{0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 	opt, err := dhcpv6.ParseOptIAForPrefixDelegation(iapd)
@@ -247,8 +237,7 @@ func (c *Client) solicit(solicit dhcpv6.DHCPv6) (dhcpv6.DHCPv6, dhcpv6.DHCPv6, e
 	return solicit, advertise, err
 }
 
-func (c *Client) request(advertise dhcpv6.DHCPv6) (dhcpv6.DHCPv6, dhcpv6.DHCPv6, error) {
-
+func (c *Client) request(advertise *dhcpv6.Message) (*dhcpv6.Message, *dhcpv6.Message, error) {
 	request, err := dhcpv6.NewRequestFromAdvertise(advertise, dhcpv6.WithClientID(*c.duid))
 	if err != nil {
 		return nil, nil, err
@@ -260,7 +249,7 @@ func (c *Client) request(advertise dhcpv6.DHCPv6) (dhcpv6.DHCPv6, dhcpv6.DHCPv6,
 	if len(c.transactionIDs) > 0 {
 		id := c.transactionIDs[0]
 		c.transactionIDs = c.transactionIDs[1:]
-		request.(*dhcpv6.DHCPv6Message).SetTransactionID(id)
+		request.TransactionID = id
 	}
 	reply, err := c.sendReceive(request, dhcpv6.MessageTypeNone)
 	return request, reply, err
@@ -281,7 +270,7 @@ func (c *Client) ObtainOrRenew() bool {
 		return true
 	}
 	var newCfg Config
-	for _, opt := range reply.Options() {
+	for _, opt := range reply.Options {
 		switch o := opt.(type) {
 		case *dhcpv6.OptIAForPrefixDelegation:
 			t1 := c.timeNow().Add(time.Duration(o.T1) * time.Second)
@@ -306,17 +295,17 @@ func (c *Client) ObtainOrRenew() bool {
 	return true
 }
 
-func (c *Client) Release() (release dhcpv6.DHCPv6, reply dhcpv6.DHCPv6, err error) {
+func (c *Client) Release() (release *dhcpv6.Message, reply *dhcpv6.Message, err error) {
 	release, err = dhcpv6.NewRequestFromAdvertise(c.advertise, dhcpv6.WithClientID(*c.duid))
 	if err != nil {
 		return nil, nil, err
 	}
-	release.(*dhcpv6.DHCPv6Message).SetMessage(dhcpv6.MessageTypeRelease)
+	release.MessageType = dhcpv6.MessageTypeRelease
 
 	if len(c.transactionIDs) > 0 {
 		id := c.transactionIDs[0]
 		c.transactionIDs = c.transactionIDs[1:]
-		release.(*dhcpv6.DHCPv6Message).SetTransactionID(id)
+		release.TransactionID = id
 	}
 	reply, err = c.sendReceive(release, dhcpv6.MessageTypeNone)
 	return release, reply, err