diff --git a/core/genesis.go b/core/genesis.go
index fd6ed6115..8f07323dc 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -191,6 +191,8 @@ func SetupGenesisBlock(db ethdb.Database, genesis *Genesis) (*params.ChainConfig
 	// config is supplied. These chains would get AllProtocolChanges (and a compat error)
 	// if we just continued here.
 	if genesis == nil && stored != params.MainnetGenesisHash {
+		log.Info("Reconfiguring old genesis as Quorum")
+		storedcfg.IsQuorum = true
 		return storedcfg, stored, nil
 	}
 
diff --git a/params/config.go b/params/config.go
index f96956e52..332501583 100644
--- a/params/config.go
+++ b/params/config.go
@@ -86,7 +86,7 @@ var (
 	// means that all fields must be set at all times. This forces
 	// anyone adding flags to the config to also have to set these
 	// fields.
-	AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(math.MaxInt64) /*disabled*/, new(EthashConfig), nil, false}
+	AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(math.MaxInt64) /*disabled*/, new(EthashConfig), nil, true}
 	TestChainConfig    = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), nil, new(EthashConfig), nil, false}
 	TestRules          = TestChainConfig.Rules(new(big.Int))
 
@@ -151,7 +151,7 @@ func (c *ChainConfig) String() string {
 	default:
 		engine = "unknown"
 	}
-	return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Metropolis: %v Engine: %v}",
+	return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Metropolis: %v IsQuorum: %v Engine: %v}",
 		c.ChainId,
 		c.HomesteadBlock,
 		c.DAOForkBlock,
@@ -160,6 +160,7 @@ func (c *ChainConfig) String() string {
 		c.EIP155Block,
 		c.EIP158Block,
 		c.MetropolisBlock,
+		c.IsQuorum,
 		engine,
 	)
 }