diff --git a/tlv/tlv.go b/tlv/tlv.go
index 8daab3c..5c19e88 100644
--- a/tlv/tlv.go
+++ b/tlv/tlv.go
@@ -508,6 +508,7 @@ type Update struct {
 	Interval uint16
 	Seqno    uint16
 	Metric   uint16
+	RouterID RouterID
 	Prefix   netaddr.IPPrefix
 	NextHop  netaddr.IP
 }
@@ -521,8 +522,8 @@ func (u Update) L() uint8 {
 }
 
 func (u Update) FormatHeader() string {
-	return fmt.Sprintf("Flags 0x%02x Omitted %2d Interval %4d Seqno %5d Metric %5d NextHop %s",
-		u.Flags, u.Omitted, u.Interval, u.Seqno, u.Metric, u.NextHop,
+	return fmt.Sprintf("Flags 0x%02x Omitted %2d Interval %4d Seqno %5d Metric %5d RouterID %s",
+		u.Flags, u.Omitted, u.Interval, u.Seqno, u.Metric, u.RouterID,
 	)
 }
 
@@ -561,6 +562,21 @@ func (s *PacketDecoder) UpdateFromBytes(b []byte) (Update, []byte, error) {
 		u.NextHop = s.nexthopv6
 	}
 
+	if u.Flags&0x40 > 0 {
+		addr := u.Prefix.IP()
+		switch {
+		case addr.Is6():
+			v6 := addr.As16()
+			copy(s.routerID[:], v6[8:])
+		case addr.Is4():
+			s.routerID = RouterID{}
+			v4 := addr.As4()
+			copy(s.routerID[4:], v4[:])
+		}
+	}
+
+	u.RouterID = s.routerID
+
 	return u, b, err
 }