diff --git a/claimtrie/claimtrie.go b/claimtrie/claimtrie.go
index 04352485..55b75c71 100644
--- a/claimtrie/claimtrie.go
+++ b/claimtrie/claimtrie.go
@@ -280,7 +280,8 @@ func (ct *ClaimTrie) AppendBlock() error {
 }
 
 func (ct *ClaimTrie) updateTrieForHashForkIfNecessary() bool {
-	if ct.height != param.ActiveParams.AllClaimsInMerkleForkHeight {
+	if ct.height != param.ActiveParams.AllClaimsInMerkleForkHeight &&
+		ct.height != param.ActiveParams.GrandForkHeight {
 		return false
 	}
 
diff --git a/claimtrie/node/hash_manager.go b/claimtrie/node/hash_manager.go
index 4892cac4..8c4fc213 100644
--- a/claimtrie/node/hash_manager.go
+++ b/claimtrie/node/hash_manager.go
@@ -1,9 +1,12 @@
 package node
 
 import (
+	"crypto/sha256"
+	"encoding/binary"
+
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
-	"github.com/lbryio/chain/claimtrie/change"
-	"github.com/lbryio/chain/claimtrie/param"
+	"github.com/btcsuite/btcd/claimtrie/change"
+	"github.com/btcsuite/btcd/claimtrie/param"
 )
 
 type HashV2Manager struct {
@@ -50,14 +53,59 @@ func (nm *HashV3Manager) AppendChange(chg change.Change) {
 	nm.Manager.AppendChange(chg)
 }
 
+func calculateBidSeqNameHash(name []byte, c *Claim, bid, takeover int32) (*chainhash.Hash, error) {
+
+	s := sha256.New()
+
+	s.Write(c.OutPoint.Hash[:])
+
+	var temp [4]byte
+	binary.BigEndian.PutUint32(temp[:], c.OutPoint.Index)
+	s.Write(temp[:])
+
+	binary.BigEndian.PutUint32(temp[:], uint32(bid))
+	s.Write(temp[:])
+
+	binary.BigEndian.PutUint32(temp[:], uint32(c.Sequence))
+	s.Write(temp[:])
+
+	binary.BigEndian.PutUint32(temp[:], uint32(takeover))
+	s.Write(temp[:])
+
+	s.Write(name)
+
+	var m [sha256.Size]byte
+	return chainhash.NewHash(s.Sum(m[:0]))
+}
+
+func (nm *HashV3Manager) bidSeqNameHash(name []byte) (*chainhash.Hash, int32) {
+	n, err := nm.NodeAt(nm.Height(), name)
+	if err != nil || n == nil {
+		return nil, 0
+	}
+
+	n.SortClaimsByBid()
+	claimHashes := make([]*chainhash.Hash, 0, len(n.Claims))
+	for i, c := range n.Claims {
+		if c.Status == Activated {
+			h, _ := calculateBidSeqNameHash(name, c, int32(i), n.TakenOverAt)
+			claimHashes = append(claimHashes, h)
+		}
+	}
+	if len(claimHashes) > 0 {
+		return ComputeMerkleRoot(claimHashes), n.NextUpdate(nm.Height())
+	}
+	return nil, n.NextUpdate(nm.Height())
+}
+
 func (nm *HashV3Manager) Hash(name []byte) (*chainhash.Hash, int32) {
 
 	if nm.Height() >= param.ActiveParams.GrandForkHeight {
 		if len(name) == 0 {
 			return nil, 0 // empty name's claims are not included in the hash
 		}
-		// return nm.detailHash()
+		return nm.bidSeqNameHash(name)
 	}
 
 	return nm.Manager.Hash(name)
-}
+}
\ No newline at end of file