diff --git a/api/api_public_blockchain.go b/api/api_public_blockchain.go
index 3dfb1bac5..7fa14b355 100644
--- a/api/api_public_blockchain.go
+++ b/api/api_public_blockchain.go
@@ -614,13 +614,13 @@ func getFrom(tx *types.Transaction) common.Address {
 	return from
 }
 
-func NewRPCTransaction(b *types.Block, tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64, config *params.ChainConfig) map[string]interface{} {
-	return newRPCTransaction(b, tx, blockHash, blockNumber, index, config)
+func NewRPCTransaction(head *types.Header, tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64, config *params.ChainConfig) map[string]interface{} {
+	return newRPCTransaction(head, tx, blockHash, blockNumber, index, config)
 }
 
 // newRPCTransaction returns a transaction that will serialize to the RPC
 // representation, with the given location metadata set (if available).
-func newRPCTransaction(b *types.Block, tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64, config *params.ChainConfig) map[string]interface{} {
+func newRPCTransaction(header *types.Header, tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64, config *params.ChainConfig) map[string]interface{} {
 	output := tx.MakeRPCOutput()
 	output["senderTxHash"] = tx.SenderTxHashAll()
 	output["blockHash"] = blockHash
@@ -629,8 +629,8 @@ func newRPCTransaction(b *types.Block, tx *types.Transaction, blockHash common.H
 	output["hash"] = tx.Hash()
 	output["transactionIndex"] = hexutil.Uint(index)
 	if tx.Type() == types.TxTypeEthereumDynamicFee {
-		if b != nil {
-			output["gasPrice"] = (*hexutil.Big)(tx.EffectiveGasPrice(b.Header(), config))
+		if header != nil {
+			output["gasPrice"] = (*hexutil.Big)(tx.EffectiveGasPrice(header, config))
 		} else {
 			// transaction is not processed yet
 			output["gasPrice"] = (*hexutil.Big)(tx.EffectiveGasPrice(nil, nil))
@@ -646,12 +646,13 @@ func newRPCPendingTransaction(tx *types.Transaction, config *params.ChainConfig)
 }
 
 // newRPCTransactionFromBlockIndex returns a transaction that will serialize to the RPC representation.
+// non-null of b(block) is guaranteed
 func newRPCTransactionFromBlockIndex(b *types.Block, index uint64, config *params.ChainConfig) map[string]interface{} {
 	txs := b.Transactions()
 	if index >= uint64(len(txs)) {
 		return nil
 	}
-	return newRPCTransaction(b, txs[index], b.Hash(), b.NumberU64(), index, config)
+	return newRPCTransaction(b.Header(), txs[index], b.Hash(), b.NumberU64(), index, config)
 }
 
 // newRPCRawTransactionFromBlockIndex returns the bytes of a transaction given a block and a transaction index.
diff --git a/api/api_public_transaction_pool.go b/api/api_public_transaction_pool.go
index c7c7ad976..865db33da 100644
--- a/api/api_public_transaction_pool.go
+++ b/api/api_public_transaction_pool.go
@@ -135,7 +135,11 @@ func (s *PublicTransactionPoolAPI) GetTransactionBySenderTxHash(ctx context.Cont
 func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) map[string]interface{} {
 	// Try to return an already finalized transaction
 	if tx, blockHash, blockNumber, index := s.b.ChainDB().ReadTxAndLookupInfo(hash); tx != nil {
-		return newRPCTransaction(nil, tx, blockHash, blockNumber, index, s.b.ChainConfig())
+		header, err := s.b.HeaderByHash(ctx, blockHash)
+		if err != nil {
+			return nil
+		}
+		return newRPCTransaction(header, tx, blockHash, blockNumber, index, s.b.ChainConfig())
 	}
 	// No finalized transaction, try to retrieve it from the pool
 	if tx := s.b.GetPoolTransaction(hash); tx != nil {
@@ -210,7 +214,7 @@ func RpcOutputReceipt(header *types.Header, tx *types.Transaction, blockHash com
 		return nil
 	}
 
-	fields := newRPCTransaction(nil, tx, blockHash, blockNumber, index, config)
+	fields := newRPCTransaction(header, tx, blockHash, blockNumber, index, config)
 
 	if receipt.Status != types.ReceiptStatusSuccessful {
 		fields["status"] = hexutil.Uint(types.ReceiptStatusFailed)
diff --git a/consensus/istanbul/backend/api.go b/consensus/istanbul/backend/api.go
index d8efb8865..63ea5a7a9 100644
--- a/consensus/istanbul/backend/api.go
+++ b/consensus/istanbul/backend/api.go
@@ -328,7 +328,7 @@ func (api *APIExtension) makeRPCBlockOutput(b *types.Block,
 			rpcTransactions[i] = kaiaApi.RpcOutputReceipt(head, tx, hash, head.Number.Uint64(), uint64(i), receipts[i], api.chain.Config())
 		} else {
 			// fill the transaction output if receipt is not found
-			rpcTransactions[i] = kaiaApi.NewRPCTransaction(b, tx, hash, head.Number.Uint64(), uint64(i), api.chain.Config())
+			rpcTransactions[i] = kaiaApi.NewRPCTransaction(head, tx, hash, head.Number.Uint64(), uint64(i), api.chain.Config())
 		}
 	}