diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
index 10c0db70f..fa04214c2 100644
--- a/accounts/keystore/keystore.go
+++ b/accounts/keystore/keystore.go
@@ -278,7 +278,7 @@ func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *b
 		return nil, ErrLocked
 	}
 	// Depending on the presence of the chain ID, sign with EIP155 or homestead
-	if chainID != nil && !isQuorum {
+	if chainID != nil && !tx.IsPrivate() {
 		return types.SignTx(tx, types.NewEIP155Signer(chainID), unlockedKey.PrivateKey)
 	}
 	return types.SignTx(tx, types.HomesteadSigner{}, unlockedKey.PrivateKey)
diff --git a/core/types/transaction.go b/core/types/transaction.go
index 80335f1da..31f88ff14 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -133,9 +133,7 @@ func isProtectedV(V *big.Int) bool {
 	if V.BitLen() <= 8 {
 		v := V.Uint64()
 		// 27 / 28 are pre eip 155 -- ie unprotected.
-		// TODO(joel): this is a hack. Everywhere else we maintain vanilla ethereum
-		// compatibility and we should figure out how to extend that to here
-		return !(v == 27 || v == 28 || v == 37 || v == 38)
+		return !(v == 27 || v == 28)
 	}
 	// anything not 27 or 28 are considered unprotected
 	return true
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index e2106bd27..2e3e154c7 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -27,6 +27,9 @@ import (
 	"bytes"
 	"encoding/hex"
 	"encoding/json"
+	"net/http"
+	"sync"
+
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/common"
@@ -45,8 +48,6 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/util"
-	"net/http"
-	"sync"
 )
 
 const (
@@ -378,7 +379,7 @@ func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs
 	tx := args.toTransaction()
 
 	var chainID *big.Int
-	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) {
+	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) && !isPrivate {
 		chainID = config.ChainId
 	}
 	signed, err := wallet.SignTxWithPassphrase(account, passwd, tx, chainID)
@@ -835,7 +836,7 @@ type RPCTransaction struct {
 func newRPCTransaction(tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64) *RPCTransaction {
 	var signer types.Signer = types.HomesteadSigner{}
 	// joel: this is one of the two places we used a wrong signer to print txes
-	if tx.Protected() {
+	if tx.Protected() && !tx.IsPrivate() {
 		signer = types.NewEIP155Signer(tx.ChainId())
 	}
 	from, _ := types.Sender(signer, tx)
@@ -1005,7 +1006,7 @@ func (s *PublicTransactionPoolAPI) GetTransactionReceipt(hash common.Hash) (map[
 	receipt, _, _, _ := core.GetReceipt(s.b.ChainDb(), hash) // Old receipts don't have the lookup data available
 
 	var signer types.Signer = types.HomesteadSigner{}
-	if tx.Protected() {
+	if tx.Protected() && !tx.IsPrivate() {
 		signer = types.NewEIP155Signer(tx.ChainId())
 	}
 	from, _ := types.Sender(signer, tx)
@@ -1051,10 +1052,9 @@ func (s *PublicTransactionPoolAPI) sign(addr common.Address, tx *types.Transacti
 	}
 	// Request the wallet to sign the transaction
 	var chainID *big.Int
-	isQuorum := false
-	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) {
+	isQuorum := tx.IsPrivate()
+	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) && !tx.IsPrivate() {
 		chainID = config.ChainId
-		isQuorum = true
 	}
 	return wallet.SignTx(account, tx, chainID, isQuorum)
 }
@@ -1169,10 +1169,9 @@ func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args Sen
 	tx := args.toTransaction()
 
 	var chainID *big.Int
-	isQuorum := false
-	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) {
+	isQuorum := tx.IsPrivate()
+	if config := s.b.ChainConfig(); config.IsEIP155(s.b.CurrentBlock().Number()) && !isPrivate {
 		chainID = config.ChainId
-		isQuorum = true
 	}
 	signed, err := wallet.SignTx(account, tx, chainID, isQuorum)
 	if err != nil {
@@ -1257,7 +1256,7 @@ func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, err
 	transactions := make([]*RPCTransaction, 0, len(pending))
 	for _, tx := range pending {
 		var signer types.Signer = types.HomesteadSigner{}
-		if tx.Protected() {
+		if tx.Protected() && !tx.IsPrivate() {
 			signer = types.NewEIP155Signer(tx.ChainId())
 		}
 		from, _ := types.Sender(signer, tx)
@@ -1285,7 +1284,7 @@ func (s *PublicTransactionPoolAPI) Resend(ctx context.Context, sendArgs SendTxAr
 
 	for _, p := range pending {
 		var signer types.Signer = types.HomesteadSigner{}
-		if p.Protected() {
+		if p.Protected() && !p.IsPrivate() {
 			signer = types.NewEIP155Signer(p.ChainId())
 		}
 		wantSigHash := signer.Hash(matchTx)