diff --git a/graph/bolt/migrate.go b/graph/bolt/migrate.go
index 2929c55..15ce577 100644
--- a/graph/bolt/migrate.go
+++ b/graph/bolt/migrate.go
@@ -15,14 +15,16 @@
 package bolt
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/barakmich/glog"
 	"github.com/boltdb/bolt"
 	"github.com/google/cayley/graph"
+	"github.com/google/cayley/graph/proto"
 )
 
-const latestDataVersion = 1
+const latestDataVersion = 2
 const nilDataVersion = 1
 
 type upgradeFunc func(*bolt.DB) error
@@ -65,6 +67,7 @@ func upgradeBolt(path string, opts graph.Options) error {
 		if err != nil {
 			return err
 		}
+		setVersion(db, i+1)
 	}
 
 	return nil
@@ -77,6 +80,64 @@ func upgrade1To2(db *bolt.DB) error {
 		return err
 	}
 	defer tx.Rollback()
+	fmt.Println("Upgrading bucket", string(logBucket))
+	lb := tx.Bucket(logBucket)
+	c := lb.Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		var delta graph.Delta
+		err := json.Unmarshal(v, &delta)
+		if err != nil {
+			return err
+		}
+		var newd proto.LogDelta
+		newd.ID = uint64(delta.ID.Int())
+		newd.Action = int32(delta.Action)
+		newd.Timestamp = delta.Timestamp.UnixNano()
+		newd.Quad = &proto.Quad{
+			Subject:   delta.Quad.Subject,
+			Predicate: delta.Quad.Predicate,
+			Object:    delta.Quad.Object,
+			Label:     delta.Quad.Label,
+		}
+		data, err := newd.Marshal()
+		if err != nil {
+			return err
+		}
+		lb.Put(k, data)
+	}
+	fmt.Println("Upgrading bucket", string(nodeBucket))
+	nb := tx.Bucket(nodeBucket)
+	c = nb.Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		var vd proto.NodeData
+		err := json.Unmarshal(v, &vd)
+		if err != nil {
+			return err
+		}
+		data, err := vd.Marshal()
+		if err != nil {
+			return err
+		}
+		nb.Put(k, data)
+	}
+
+	for _, bucket := range [4][]byte{spoBucket, ospBucket, posBucket, cpsBucket} {
+		fmt.Println("Upgrading bucket", string(bucket))
+		b := tx.Bucket(bucket)
+		cur := b.Cursor()
+		for k, v := cur.First(); k != nil; k, v = cur.Next() {
+			var h proto.HistoryEntry
+			err := json.Unmarshal(v, &h)
+			if err != nil {
+				return err
+			}
+			data, err := h.Marshal()
+			if err != nil {
+				return err
+			}
+			b.Put(k, data)
+		}
+	}
 	if err := tx.Commit(); err != nil {
 		return err
 	}
diff --git a/graph/bolt/quadstore.go b/graph/bolt/quadstore.go
index 55115b7..8aa0a28 100644
--- a/graph/bolt/quadstore.go
+++ b/graph/bolt/quadstore.go
@@ -89,7 +89,7 @@ func createNewBolt(path string, _ graph.Options) error {
 	if err != nil {
 		return err
 	}
-	err = qs.setVersion(latestDataVersion)
+	err = setVersion(qs.db, latestDataVersion)
 	if err != nil {
 		return err
 	}
@@ -148,8 +148,8 @@ func (qs *QuadStore) createBuckets() error {
 	})
 }
 
-func (qs *QuadStore) setVersion(version int) error {
-	return qs.db.Update(func(tx *bolt.Tx) error {
+func setVersion(db *bolt.DB, version int64) error {
+	return db.Update(func(tx *bolt.Tx) error {
 		buf := new(bytes.Buffer)
 		err := binary.Write(buf, binary.LittleEndian, version)
 		if err != nil {
diff --git a/graph/proto/serializations.pb.go b/graph/proto/serializations.pb.go
index 2b7e839..30b24d4 100644
--- a/graph/proto/serializations.pb.go
+++ b/graph/proto/serializations.pb.go
@@ -28,7 +28,7 @@ type LogDelta struct {
 	ID        uint64 `protobuf:"varint,1,opt,proto3" json:"ID,omitempty"`
 	Quad      *Quad  `protobuf:"bytes,2,opt" json:"Quad,omitempty"`
 	Action    int32  `protobuf:"varint,3,opt,proto3" json:"Action,omitempty"`
-	Timestamp uint64 `protobuf:"varint,4,opt,proto3" json:"Timestamp,omitempty"`
+	Timestamp int64  `protobuf:"varint,4,opt,proto3" json:"Timestamp,omitempty"`
 }
 
 func (m *LogDelta) Reset()         { *m = LogDelta{} }
@@ -158,7 +158,7 @@ func (m *LogDelta) Unmarshal(data []byte) error {
 				}
 				b := data[iNdEx]
 				iNdEx++
-				m.Timestamp |= (uint64(b) & 0x7F) << shift
+				m.Timestamp |= (int64(b) & 0x7F) << shift
 				if b < 0x80 {
 					break
 				}
diff --git a/graph/proto/serializations.proto b/graph/proto/serializations.proto
index 30155b6..ee8295d 100644
--- a/graph/proto/serializations.proto
+++ b/graph/proto/serializations.proto
@@ -20,7 +20,7 @@ message LogDelta {
   uint64 ID = 1;
   Quad Quad = 2;
   int32 Action = 3;
-  uint64 Timestamp = 4;
+  int64 Timestamp = 4;
 }
 
 message HistoryEntry {