diff --git a/import.go b/import.go
index 282e260ca..2379de6de 100644
--- a/import.go
+++ b/import.go
@@ -68,15 +68,27 @@ func (i *Importer) writeNode(node *Node) error {
 	buf.Reset()
 	defer bufPool.Put(buf)
 
-	if err := node.writeBytes(buf); err != nil {
-		return err
+	if i.tree.useLegacyFormat {
+		if err := node.writeLegacyBytes(buf); err != nil {
+			return err
+		}
+	} else {
+		if err := node.writeBytes(buf); err != nil {
+			return err
+		}
 	}
 
 	bytesCopy := make([]byte, buf.Len())
 	copy(bytesCopy, buf.Bytes())
 
-	if err := i.batch.Set(i.tree.ndb.nodeKey(node.GetKey()), bytesCopy); err != nil {
-		return err
+	if i.tree.useLegacyFormat {
+		if err := i.batch.Set(i.tree.ndb.legacyNodeKey(node.GetKey()), bytesCopy); err != nil {
+			return err
+		}
+	} else {
+		if err := i.batch.Set(i.tree.ndb.nodeKey(node.GetKey()), bytesCopy); err != nil {
+			return err
+		}
 	}
 
 	i.batchSize++
diff --git a/mutable_tree.go b/mutable_tree.go
index 596d8b22c..e3890c0f3 100644
--- a/mutable_tree.go
+++ b/mutable_tree.go
@@ -285,7 +285,7 @@ func (tree *MutableTree) set(key []byte, value []byte) (updated bool, err error)
 		if !tree.skipFastStorageUpgrade {
 			tree.addUnsavedAddition(key, fastnode.NewNode(key, value, tree.version+1))
 		}
-		tree.ImmutableTree.root = NewNode(key, value)
+		tree.ImmutableTree.root = NewNode(key, value, tree.useLegacyFormat)
 		return updated, nil
 	}
 
@@ -344,7 +344,7 @@ func (tree *MutableTree) recursiveSetLeaf(node *Node, key []byte, value []byte)
 			subtreeHeight: 1,
 			size:          2,
 			nodeKey:       nil,
-			leftNode:      NewNode(key, value),
+			leftNode:      NewNode(key, value, tree.useLegacyFormat),
 			rightNode:     node,
 		}, false, nil
 	case 1: // setKey > leafKey
@@ -354,10 +354,10 @@ func (tree *MutableTree) recursiveSetLeaf(node *Node, key []byte, value []byte)
 			size:          2,
 			nodeKey:       nil,
 			leftNode:      node,
-			rightNode:     NewNode(key, value),
+			rightNode:     NewNode(key, value, tree.useLegacyFormat),
 		}, false, nil
 	default:
-		return NewNode(key, value), true, nil
+		return NewNode(key, value, tree.useLegacyFormat), true, nil
 	}
 }
 
@@ -805,17 +805,30 @@ func (tree *MutableTree) SaveVersion() ([]byte, int64, error) {
 	} else {
 		if tree.root.nodeKey != nil {
 			// it means there are no updated nodes
-			if err := tree.ndb.SaveRoot(version, tree.root.nodeKey); err != nil {
-				return nil, 0, err
-			}
-			// it means the reference node is a legacy node
-			if tree.root.isLegacy {
-				// it will update the legacy node to the new format
-				// which ensures the reference node is not a legacy node
-				tree.root.isLegacy = tree.useLegacyFormat
+			if tree.useLegacyFormat {
+				if len(tree.root.hash) == 0 {
+					tree.root._hash(version)
+				}
+				if err := tree.ndb.SaveLegacyRoot(version, tree.root.hash); err != nil {
+					return nil, 0, err
+				}
+				tree.root.isLegacy = true
 				if err := tree.ndb.SaveNode(tree.root); err != nil {
 					return nil, 0, fmt.Errorf("failed to save the reference legacy node: %w", err)
 				}
+			} else {
+				if err := tree.ndb.SaveRoot(version, tree.root.nodeKey); err != nil {
+					return nil, 0, err
+				}
+				// it means the reference node is a legacy node
+				if tree.root.isLegacy {
+					// it will update the legacy node to the new format
+					// which ensures the reference node is not a legacy node
+					tree.root.isLegacy = false
+					if err := tree.ndb.SaveNode(tree.root); err != nil {
+						return nil, 0, fmt.Errorf("failed to save the reference legacy node: %w", err)
+					}
+				}
 			}
 		} else {
 			if err := tree.saveNewNodes(version); err != nil {
@@ -1080,16 +1093,14 @@ func (tree *MutableTree) saveNewNodes(version int64) error {
 	var recursiveAssignKey func(*Node) ([]byte, error)
 	recursiveAssignKey = func(node *Node) ([]byte, error) {
 		node.isLegacy = tree.useLegacyFormat
-		if node.nodeKey != nil || (node.isLegacy && node.hash != nil) {
+		if (!node.isLegacy && node.nodeKey != nil) || (node.isLegacy && node.hash != nil) {
 			return node.GetKey(), nil
 		}
 
-		if !node.isLegacy {
-			nonce++
-			node.nodeKey = &NodeKey{
-				version: version,
-				nonce:   nonce,
-			}
+		nonce++
+		node.nodeKey = &NodeKey{
+			version: version,
+			nonce:   nonce,
 		}
 
 		var err error
diff --git a/node.go b/node.go
index 06ffc9e58..b7aa51e3b 100644
--- a/node.go
+++ b/node.go
@@ -77,12 +77,13 @@ type Node struct {
 var _ cache.Node = (*Node)(nil)
 
 // NewNode returns a new node from a key, value and version.
-func NewNode(key []byte, value []byte) *Node {
+func NewNode(key []byte, value []byte, useLegacy bool) *Node {
 	return &Node{
 		key:           key,
 		value:         value,
 		subtreeHeight: 0,
 		size:          1,
+		isLegacy:      useLegacy,
 	}
 }
 
@@ -243,11 +244,9 @@ func MakeLegacyNode(hash, buf []byte) (*Node, error) {
 		nodeKey:       &NodeKey{version: ver},
 		key:           key,
 		hash:          hash,
-		isLegacy:      true,
 	}
 
 	// Read node body.
-
 	if node.isLeaf() {
 		val, _, err := encoding.DecodeBytes(buf)
 		if err != nil {
@@ -268,6 +267,7 @@ func MakeLegacyNode(hash, buf []byte) (*Node, error) {
 		node.leftNodeKey = leftHash
 		node.rightNodeKey = rightHash
 	}
+	//fmt.Printf("legacy node: %+v\r\n", *node)
 	return node, nil
 }
 
@@ -612,6 +612,9 @@ func (node *Node) writeBytes(w io.Writer) error {
 		if node.leftNodeKey == nil {
 			return ErrLeftNodeKeyEmpty
 		}
+		if node.rightNodeKey == nil {
+			return ErrRightNodeKeyEmpty
+		}
 		// check if children NodeKeys are legacy mode
 		if len(node.leftNodeKey) == hashSize {
 			mode += ModeLegacyLeftNode
@@ -662,6 +665,54 @@ func (node *Node) writeBytes(w io.Writer) error {
 	return nil
 }
 
+func (node *Node) writeLegacyBytes(w io.Writer) error {
+	if node == nil {
+		return errors.New("cannot write nil node")
+	}
+	err := encoding.EncodeVarint(w, int64(node.subtreeHeight))
+	if err != nil {
+		return fmt.Errorf("writing height, %w", err)
+	}
+	err = encoding.EncodeVarint(w, node.size)
+	if err != nil {
+		return fmt.Errorf("writing size, %w", err)
+	}
+	err = encoding.EncodeVarint(w, node.nodeKey.version)
+	if err != nil {
+		return fmt.Errorf("writing version, %w", err)
+	}
+
+	// Unlike writeHashBytes, key is written for inner nodes.
+	err = encoding.EncodeBytes(w, node.key)
+	if err != nil {
+		return fmt.Errorf("writing key, %w", err)
+	}
+
+	if node.isLeaf() {
+		err = encoding.EncodeBytes(w, node.value)
+		if err != nil {
+			return fmt.Errorf("writing value, %w", err)
+		}
+	} else {
+		if len(node.leftNodeKey) != hashSize {
+			return errors.New("node provided to writeLegacyBytes does not have a hash for leftNodeKey")
+		}
+		err = encoding.EncodeBytes(w, node.leftNodeKey)
+		if err != nil {
+			return fmt.Errorf("writing left hash, %w", err)
+		}
+
+		if len(node.leftNodeKey) != 32 {
+			return errors.New("node provided to writeLegacyBytes does not have a hash for rightNodeKey")
+		}
+		err = encoding.EncodeBytes(w, node.rightNodeKey)
+		if err != nil {
+			return fmt.Errorf("writing right hash, %w", err)
+		}
+	}
+	return nil
+}
+
 func (node *Node) getLeftNode(t *ImmutableTree) (*Node, error) {
 	if node.leftNode != nil {
 		return node.leftNode, nil
diff --git a/nodedb.go b/nodedb.go
index 334c4e588..2aae2cf4d 100644
--- a/nodedb.go
+++ b/nodedb.go
@@ -164,9 +164,9 @@ func (ndb *nodeDB) GetNode(nk []byte) (*Node, error) {
 	ndb.opts.Stat.IncCacheMissCnt()
 
 	// Doesn't exist, load.
-	isLegcyNode := len(nk) == hashSize
+	isLegacyNode := len(nk) == hashSize
 	var nodeKey []byte
-	if isLegcyNode {
+	if isLegacyNode {
 		nodeKey = ndb.legacyNodeKey(nk)
 	} else {
 		nodeKey = ndb.nodeKey(nk)
@@ -180,11 +180,12 @@ func (ndb *nodeDB) GetNode(nk []byte) (*Node, error) {
 	}
 
 	var node *Node
-	if isLegcyNode {
+	if isLegacyNode {
 		node, err = MakeLegacyNode(nk, buf)
 		if err != nil {
 			return nil, fmt.Errorf("error reading Legacy Node. bytes: %x, error: %v", buf, err)
 		}
+		node.isLegacy = ndb.useLegacyFormat
 	} else {
 		node, err = MakeNode(nk, buf)
 		if err != nil {
@@ -238,7 +239,7 @@ func (ndb *nodeDB) SaveNode(node *Node) error {
 	ndb.mtx.Lock()
 	defer ndb.mtx.Unlock()
 
-	if (node.nodeKey == nil && !node.isLegacy) || (node.hash == nil && node.isLegacy) {
+	if node.nodeKey == nil || (ndb.useLegacyFormat && node.hash == nil) {
 		return ErrNodeMissingNodeKey
 	}
 
@@ -246,12 +247,21 @@ func (ndb *nodeDB) SaveNode(node *Node) error {
 	var buf bytes.Buffer
 	buf.Grow(node.encodedSize())
 
-	if err := node.writeBytes(&buf); err != nil {
-		return err
-	}
-
-	if err := ndb.batch.Set(ndb.nodeKey(node.GetKey()), buf.Bytes()); err != nil {
-		return err
+	nk := node.GetKey()
+	if len(nk) == hashSize {
+		if err := node.writeLegacyBytes(&buf); err != nil {
+			return err
+		}
+		if err := ndb.batch.Set(ndb.legacyNodeKey(nk), buf.Bytes()); err != nil {
+			return err
+		}
+	} else {
+		if err := node.writeBytes(&buf); err != nil {
+			return err
+		}
+		if err := ndb.batch.Set(ndb.nodeKey(nk), buf.Bytes()); err != nil {
+			return err
+		}
 	}
 
 	ndb.logger.Debug("BATCH SAVE", "node", node)
@@ -357,6 +367,9 @@ func (ndb *nodeDB) saveFastNodeUnlocked(node *fastnode.Node, shouldAddToCache bo
 
 // Has checks if a node key exists in the database.
 func (ndb *nodeDB) Has(nk []byte) (bool, error) {
+	if len(nk) == hashSize {
+		return ndb.db.Has(ndb.legacyNodeKey(nk))
+	}
 	return ndb.db.Has(ndb.nodeKey(nk))
 }
 
@@ -860,6 +873,13 @@ func (ndb *nodeDB) SaveRoot(version int64, nk *NodeKey) error {
 	return ndb.batch.Set(nodeKeyFormat.Key(GetRootKey(version)), nodeKeyFormat.Key(nk.GetKey()))
 }
 
+// SaveLegacyRoot saves the root when no updates.
+func (ndb *nodeDB) SaveLegacyRoot(version int64, key []byte) error {
+	ndb.mtx.Lock()
+	defer ndb.mtx.Unlock()
+	return ndb.batch.Set(nodeKeyFormat.Key(GetRootKey(version)), legacyNodeKeyFormat.Key(key))
+}
+
 // Traverse fast nodes and return error if any, nil otherwise
 func (ndb *nodeDB) traverseFastNodes(fn func(k, v []byte) error) error {
 	return ndb.traversePrefix(fastKeyFormat.Key(), fn)
diff --git a/testutils_test.go b/testutils_test.go
index b64a54984..7bbd8f24c 100644
--- a/testutils_test.go
+++ b/testutils_test.go
@@ -52,12 +52,12 @@ func N(l, r interface{}) *Node {
 	if _, ok := l.(*Node); ok {
 		left = l.(*Node)
 	} else {
-		left = NewNode(i2b(l.(int)), nil)
+		left = NewNode(i2b(l.(int)), nil, false)
 	}
 	if _, ok := r.(*Node); ok {
 		right = r.(*Node)
 	} else {
-		right = NewNode(i2b(r.(int)), nil)
+		right = NewNode(i2b(r.(int)), nil, false)
 	}
 
 	n := &Node{