diff --git a/action/protocol/staking/contractstaking/bucket.go b/action/protocol/staking/contractstaking/bucket.go
index 0e34336acc..b663c8dd92 100644
--- a/action/protocol/staking/contractstaking/bucket.go
+++ b/action/protocol/staking/contractstaking/bucket.go
@@ -22,7 +22,7 @@ type Bucket struct {
 	StakeStartBlockHeight     uint64
 	UnstakeStartBlockHeight   uint64
 	AutoStake                 bool
-	ContractAddress           string
+	ContractAddress           string // contract address for the bucket
 }
 
 func assembleBucket(token uint64, bi *bucketInfo, bt *BucketType) (*Bucket, error) {
diff --git a/action/protocol/staking/contractstaking/bucket_info.go b/action/protocol/staking/contractstaking/bucket_info.go
index ab23043c5f..8683a66880 100644
--- a/action/protocol/staking/contractstaking/bucket_info.go
+++ b/action/protocol/staking/contractstaking/bucket_info.go
@@ -25,18 +25,6 @@ type (
 	}
 )
 
-func (bi *bucketInfo) toProto() *contractstakingpb.BucketInfo {
-	pb := &contractstakingpb.BucketInfo{
-		TypeIndex:  bi.TypeIndex,
-		Delegate:   bi.Delegate.String(),
-		CreatedAt:  bi.CreatedAt,
-		Owner:      bi.Owner.String(),
-		UnlockedAt: bi.UnlockedAt,
-		UnstakedAt: bi.UnstakedAt,
-	}
-	return pb
-}
-
 // Serialize serializes the bucket info
 func (bi *bucketInfo) Serialize() []byte {
 	return byteutil.Must(proto.Marshal(bi.toProto()))
@@ -51,19 +39,32 @@ func (bi *bucketInfo) Deserialize(b []byte) error {
 	return bi.loadProto(&m)
 }
 
+func (bi *bucketInfo) toProto() *contractstakingpb.BucketInfo {
+	pb := &contractstakingpb.BucketInfo{
+		TypeIndex:  bi.TypeIndex,
+		Delegate:   bi.Delegate.String(),
+		CreatedAt:  bi.CreatedAt,
+		Owner:      bi.Owner.String(),
+		UnlockedAt: bi.UnlockedAt,
+		UnstakedAt: bi.UnstakedAt,
+	}
+	return pb
+}
+
 func (bi *bucketInfo) loadProto(p *contractstakingpb.BucketInfo) error {
-	var err error
-	bi.TypeIndex = p.TypeIndex
-	bi.CreatedAt = p.CreatedAt
-	bi.UnlockedAt = p.UnlockedAt
-	bi.UnstakedAt = p.UnstakedAt
-	bi.Delegate, err = address.FromString(p.Delegate)
+	delegate, err := address.FromString(p.Delegate)
 	if err != nil {
 		return err
 	}
-	bi.Owner, err = address.FromString(p.Owner)
+	owner, err := address.FromString(p.Owner)
 	if err != nil {
 		return err
 	}
+	bi.TypeIndex = p.TypeIndex
+	bi.CreatedAt = p.CreatedAt
+	bi.UnlockedAt = p.UnlockedAt
+	bi.UnstakedAt = p.UnstakedAt
+	bi.Delegate = delegate
+	bi.Owner = owner
 	return nil
 }
diff --git a/action/protocol/staking/contractstaking/bucket_type.go b/action/protocol/staking/contractstaking/bucket_type.go
index f26fc5ee14..98fca73346 100644
--- a/action/protocol/staking/contractstaking/bucket_type.go
+++ b/action/protocol/staking/contractstaking/bucket_type.go
@@ -24,6 +24,20 @@ type (
 	}
 )
 
+// Serialize serializes the bucket type
+func (bt *BucketType) Serialize() []byte {
+	return byteutil.Must(proto.Marshal(bt.toProto()))
+}
+
+// Deserialize deserializes the bucket type
+func (bt *BucketType) Deserialize(b []byte) error {
+	m := contractstakingpb.BucketType{}
+	if err := proto.Unmarshal(b, &m); err != nil {
+		return err
+	}
+	return bt.loadProto(&m)
+}
+
 func (bt *BucketType) toProto() *contractstakingpb.BucketType {
 	return &contractstakingpb.BucketType{
 		Amount:      bt.Amount.String(),
@@ -33,26 +47,12 @@ func (bt *BucketType) toProto() *contractstakingpb.BucketType {
 }
 
 func (bt *BucketType) loadProto(p *contractstakingpb.BucketType) error {
-	var ok bool
-	bt.Amount, ok = big.NewInt(0).SetString(p.Amount, 10)
+	amount, ok := big.NewInt(0).SetString(p.Amount, 10)
 	if !ok {
 		return errors.New("failed to parse amount")
 	}
+	bt.Amount = amount
 	bt.Duration = p.Duration
 	bt.ActivatedAt = p.ActivatedAt
 	return nil
 }
-
-// Serialize serializes the bucket type
-func (bt *BucketType) Serialize() []byte {
-	return byteutil.Must(proto.Marshal(bt.toProto()))
-}
-
-// Deserialize deserializes the bucket type
-func (bt *BucketType) Deserialize(b []byte) error {
-	m := contractstakingpb.BucketType{}
-	if err := proto.Unmarshal(b, &m); err != nil {
-		return err
-	}
-	return bt.loadProto(&m)
-}