diff --git a/cmd/faucet/faucet.go b/cmd/faucet/faucet.go
index aa8f4bac16..fd34cdec16 100644
--- a/cmd/faucet/faucet.go
+++ b/cmd/faucet/faucet.go
@@ -41,7 +41,7 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth"
-	"github.com/ethereum/go-ethereum/eth/gasprice"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/ethstats"
 	"github.com/ethereum/go-ethereum/les"
@@ -195,16 +195,11 @@ func newFaucet(genesis *core.Genesis, port int, enodes []*discv5.Node, network i
 	}
 	// Assemble the Ethereum light client protocol
 	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
-		return les.New(ctx, &eth.Config{
-			LightMode:          true,
-			NetworkId:          network,
-			Genesis:            genesis,
-			GasPrice:           big.NewInt(20 * params.Shannon),
-			GPO:                gasprice.Config{Blocks: 10, Percentile: 50},
-			EthashCacheDir:     "ethash",
-			EthashCachesInMem:  2,
-			EthashCachesOnDisk: 3,
-		})
+		cfg := eth.DefaultConfig
+		cfg.SyncMode = downloader.LightSync
+		cfg.NetworkId = network
+		cfg.Genesis = genesis
+		return les.New(ctx, &cfg)
 	}); err != nil {
 		return nil, err
 	}
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 75e0f85e0f..068be4265d 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -37,6 +37,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethstats"
@@ -792,29 +793,33 @@ func setEthash(ctx *cli.Context, cfg *eth.Config) {
 	}
 }
 
+func checkExclusive(ctx *cli.Context, flags ...cli.BoolFlag) {
+	set := 0
+	for _, flag := range flags {
+		if ctx.GlobalIsSet(flag.Name) {
+			set++
+		}
+	}
+	if set > 1 {
+		Fatalf("The %v flags are mutually exclusive", flags)
+	}
+}
+
 // SetEthConfig applies eth-related command line flags to the config.
 func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 	// Avoid conflicting network flags
-	networks, netFlags := 0, []cli.BoolFlag{DevModeFlag, TestNetFlag}
-	for _, flag := range netFlags {
-		if ctx.GlobalBool(flag.Name) {
-			networks++
-		}
-	}
-	if networks > 1 {
-		Fatalf("The %v flags are mutually exclusive", netFlags)
-	}
+	checkExclusive(ctx, DevModeFlag, TestNetFlag)
+	checkExclusive(ctx, FastSyncFlag, LightModeFlag)
 
 	ks := stack.AccountManager().Backends(keystore.KeyStoreType)[0].(*keystore.KeyStore)
 	setEtherbase(ctx, ks, cfg)
 	setGPO(ctx, &cfg.GPO)
 	setEthash(ctx, cfg)
 
-	if ctx.GlobalIsSet(FastSyncFlag.Name) {
-		cfg.FastSync = ctx.GlobalBool(FastSyncFlag.Name)
-	}
-	if ctx.GlobalIsSet(LightModeFlag.Name) {
-		cfg.LightMode = ctx.GlobalBool(LightModeFlag.Name)
+	if ctx.GlobalBool(FastSyncFlag.Name) {
+		cfg.SyncMode = downloader.FastSync
+	} else if ctx.GlobalBool(LightModeFlag.Name) {
+		cfg.SyncMode = downloader.LightSync
 	}
 	if ctx.GlobalIsSet(LightServFlag.Name) {
 		cfg.LightServ = ctx.GlobalInt(LightServFlag.Name)
@@ -880,7 +885,7 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 // RegisterEthService adds an Ethereum client to the stack.
 func RegisterEthService(stack *node.Node, cfg *eth.Config) {
 	var err error
-	if cfg.LightMode {
+	if cfg.SyncMode == downloader.LightSync {
 		err = stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
 			return les.New(ctx, cfg)
 		})
diff --git a/eth/backend.go b/eth/backend.go
index 5152f36efc..7ee591f9eb 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -18,6 +18,7 @@
 package eth
 
 import (
+	"errors"
 	"fmt"
 	"runtime"
 	"sync"
@@ -92,6 +93,13 @@ func (s *Ethereum) AddLesServer(ls LesServer) {
 // New creates a new Ethereum object (including the
 // initialisation of the common Ethereum object)
 func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
+	if config.SyncMode == downloader.LightSync {
+		return nil, errors.New("can't run eth.Ethereum in light sync mode, use les.LightEthereum")
+	}
+	if !config.SyncMode.IsValid() {
+		return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
+	}
+
 	chainDb, err := CreateDB(ctx, config, "chaindata")
 	if err != nil {
 		return nil, err
@@ -156,7 +164,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		}
 	}
 
-	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.FastSync, config.NetworkId, maxPeers, eth.eventMux, eth.txPool, eth.engine, eth.blockchain, chainDb); err != nil {
+	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.SyncMode, config.NetworkId, maxPeers, eth.eventMux, eth.txPool, eth.engine, eth.blockchain, chainDb); err != nil {
 		return nil, err
 	}
 
diff --git a/eth/config.go b/eth/config.go
index 80ae07a92f..9ac99c6c66 100644
--- a/eth/config.go
+++ b/eth/config.go
@@ -26,12 +26,14 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/params"
 )
 
 // DefaultConfig contains default settings for use on the Ethereum main net.
 var DefaultConfig = Config{
+	SyncMode:             downloader.FullSync,
 	EthashCachesInMem:    2,
 	EthashCachesOnDisk:   3,
 	EthashDatasetsInMem:  1,
@@ -69,9 +71,8 @@ type Config struct {
 	Genesis *core.Genesis `toml:",omitempty"`
 
 	// Protocol options
-	NetworkId int  // Network ID to use for selecting peers to connect to
-	FastSync  bool // Enables the state download based fast synchronisation algorithm
-	LightMode bool // Running in light client mode
+	NetworkId int // Network ID to use for selecting peers to connect to
+	SyncMode  downloader.SyncMode
 
 	// Light client options
 	LightServ  int `toml:",omitempty"` // Maximum percentage of time allowed for serving LES requests
diff --git a/eth/downloader/modes.go b/eth/downloader/modes.go
index ae3c43888a..8ecdf91f11 100644
--- a/eth/downloader/modes.go
+++ b/eth/downloader/modes.go
@@ -16,6 +16,8 @@
 
 package downloader
 
+import "fmt"
+
 // SyncMode represents the synchronisation mode of the downloader.
 type SyncMode int
 
@@ -25,6 +27,10 @@ const (
 	LightSync                 // Download only the headers and terminate afterwards
 )
 
+func (mode SyncMode) IsValid() bool {
+	return mode >= FullSync && mode <= LightSync
+}
+
 // String implements the stringer interface.
 func (mode SyncMode) String() string {
 	switch mode {
@@ -38,3 +44,30 @@ func (mode SyncMode) String() string {
 		return "unknown"
 	}
 }
+
+func (mode SyncMode) MarshalText() ([]byte, error) {
+	switch mode {
+	case FullSync:
+		return []byte("full"), nil
+	case FastSync:
+		return []byte("fast"), nil
+	case LightSync:
+		return []byte("light"), nil
+	default:
+		return nil, fmt.Errorf("unknown sync mode %d", mode)
+	}
+}
+
+func (mode *SyncMode) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "full":
+		*mode = FullSync
+	case "fast":
+		*mode = FastSync
+	case "light":
+		*mode = LightSync
+	default:
+		return fmt.Errorf(`unknown sync mode %q, want "full", "fast" or "light"`, text)
+	}
+	return nil
+}
diff --git a/eth/gen_config.go b/eth/gen_config.go
index fc5391f1e0..d34273e1c3 100644
--- a/eth/gen_config.go
+++ b/eth/gen_config.go
@@ -8,6 +8,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 )
 
@@ -15,8 +16,7 @@ func (c Config) MarshalTOML() (interface{}, error) {
 	type Config struct {
 		Genesis                 *core.Genesis `toml:",omitempty"`
 		NetworkId               int
-		FastSync                bool
-		LightMode               bool
+		SyncMode                downloader.SyncMode
 		LightServ               int  `toml:",omitempty"`
 		LightPeers              int  `toml:",omitempty"`
 		MaxPeers                int  `toml:"-"`
@@ -44,8 +44,7 @@ func (c Config) MarshalTOML() (interface{}, error) {
 	var enc Config
 	enc.Genesis = c.Genesis
 	enc.NetworkId = c.NetworkId
-	enc.FastSync = c.FastSync
-	enc.LightMode = c.LightMode
+	enc.SyncMode = c.SyncMode
 	enc.LightServ = c.LightServ
 	enc.LightPeers = c.LightPeers
 	enc.MaxPeers = c.MaxPeers
@@ -76,8 +75,7 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 	type Config struct {
 		Genesis                 *core.Genesis `toml:",omitempty"`
 		NetworkId               *int
-		FastSync                *bool
-		LightMode               *bool
+		SyncMode                *downloader.SyncMode
 		LightServ               *int  `toml:",omitempty"`
 		LightPeers              *int  `toml:",omitempty"`
 		MaxPeers                *int  `toml:"-"`
@@ -112,11 +110,8 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 	if dec.NetworkId != nil {
 		c.NetworkId = *dec.NetworkId
 	}
-	if dec.FastSync != nil {
-		c.FastSync = *dec.FastSync
-	}
-	if dec.LightMode != nil {
-		c.LightMode = *dec.LightMode
+	if dec.SyncMode != nil {
+		c.SyncMode = *dec.SyncMode
 	}
 	if dec.LightServ != nil {
 		c.LightServ = *dec.LightServ
diff --git a/eth/handler.go b/eth/handler.go
index 99c2c4b321..fb8a0fd570 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -96,7 +96,7 @@ type ProtocolManager struct {
 
 // NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
 // with the ethereum network.
-func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int, maxPeers int, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb ethdb.Database) (*ProtocolManager, error) {
+func NewProtocolManager(config *params.ChainConfig, mode downloader.SyncMode, networkId int, maxPeers int, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb ethdb.Database) (*ProtocolManager, error) {
 	// Create the protocol manager with the base fields
 	manager := &ProtocolManager{
 		networkId:   networkId,
@@ -113,18 +113,18 @@ func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int
 		quitSync:    make(chan struct{}),
 	}
 	// Figure out whether to allow fast sync or not
-	if fastSync && blockchain.CurrentBlock().NumberU64() > 0 {
+	if mode == downloader.FastSync && blockchain.CurrentBlock().NumberU64() > 0 {
 		log.Warn("Blockchain not empty, fast sync disabled")
-		fastSync = false
+		mode = downloader.FullSync
 	}
-	if fastSync {
+	if mode == downloader.FastSync {
 		manager.fastSync = uint32(1)
 	}
 	// Initiate a sub-protocol for every implemented version we can handle
 	manager.SubProtocols = make([]p2p.Protocol, 0, len(ProtocolVersions))
 	for i, version := range ProtocolVersions {
 		// Skip protocol version if incompatible with the mode of operation
-		if fastSync && version < eth63 {
+		if mode == downloader.FastSync && version < eth63 {
 			continue
 		}
 		// Compatible; initialise the sub-protocol
@@ -159,7 +159,7 @@ func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int
 		return nil, errIncompatibleConfig
 	}
 	// Construct the different synchronisation mechanisms
-	manager.downloader = downloader.New(downloader.FullSync, chaindb, manager.eventMux, blockchain.HasHeader, blockchain.HasBlockAndState, blockchain.GetHeaderByHash,
+	manager.downloader = downloader.New(mode, chaindb, manager.eventMux, blockchain.HasHeader, blockchain.HasBlockAndState, blockchain.GetHeaderByHash,
 		blockchain.GetBlockByHash, blockchain.CurrentHeader, blockchain.CurrentBlock, blockchain.CurrentFastBlock, blockchain.FastSyncCommitHead,
 		blockchain.GetTdByHash, blockchain.InsertHeaderChain, manager.blockchain.InsertChain, blockchain.InsertReceiptChain, blockchain.Rollback,
 		manager.removePeer)
diff --git a/eth/handler_test.go b/eth/handler_test.go
index 19f6ced171..413ed2bff0 100644
--- a/eth/handler_test.go
+++ b/eth/handler_test.go
@@ -44,11 +44,11 @@ func TestProtocolCompatibility(t *testing.T) {
 	// Define the compatibility chart
 	tests := []struct {
 		version    uint
-		fastSync   bool
+		mode       downloader.SyncMode
 		compatible bool
 	}{
-		{61, false, true}, {62, false, true}, {63, false, true},
-		{61, true, false}, {62, true, false}, {63, true, true},
+		{61, downloader.FullSync, true}, {62, downloader.FullSync, true}, {63, downloader.FullSync, true},
+		{61, downloader.FastSync, false}, {62, downloader.FastSync, false}, {63, downloader.FastSync, true},
 	}
 	// Make sure anything we screw up is restored
 	backup := ProtocolVersions
@@ -58,7 +58,7 @@ func TestProtocolCompatibility(t *testing.T) {
 	for i, tt := range tests {
 		ProtocolVersions = []uint{tt.version}
 
-		pm, err := newTestProtocolManager(tt.fastSync, 0, nil, nil)
+		pm, err := newTestProtocolManager(tt.mode, 0, nil, nil)
 		if pm != nil {
 			defer pm.Stop()
 		}
@@ -73,7 +73,7 @@ func TestGetBlockHeaders62(t *testing.T) { testGetBlockHeaders(t, 62) }
 func TestGetBlockHeaders63(t *testing.T) { testGetBlockHeaders(t, 63) }
 
 func testGetBlockHeaders(t *testing.T, protocol int) {
-	pm := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, downloader.MaxHashFetch+15, nil, nil)
 	peer, _ := newTestPeer("peer", protocol, pm, true)
 	defer peer.close()
 
@@ -232,7 +232,7 @@ func TestGetBlockBodies62(t *testing.T) { testGetBlockBodies(t, 62) }
 func TestGetBlockBodies63(t *testing.T) { testGetBlockBodies(t, 63) }
 
 func testGetBlockBodies(t *testing.T, protocol int) {
-	pm := newTestProtocolManagerMust(t, false, downloader.MaxBlockFetch+15, nil, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, downloader.MaxBlockFetch+15, nil, nil)
 	peer, _ := newTestPeer("peer", protocol, pm, true)
 	defer peer.close()
 
@@ -339,7 +339,7 @@ func testGetNodeData(t *testing.T, protocol int) {
 		}
 	}
 	// Assemble the test environment
-	pm := newTestProtocolManagerMust(t, false, 4, generator, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, 4, generator, nil)
 	peer, _ := newTestPeer("peer", protocol, pm, true)
 	defer peer.close()
 
@@ -431,7 +431,7 @@ func testGetReceipt(t *testing.T, protocol int) {
 		}
 	}
 	// Assemble the test environment
-	pm := newTestProtocolManagerMust(t, false, 4, generator, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, 4, generator, nil)
 	peer, _ := newTestPeer("peer", protocol, pm, true)
 	defer peer.close()
 
@@ -476,7 +476,7 @@ func testDAOChallenge(t *testing.T, localForked, remoteForked bool, timeout bool
 		genesis       = gspec.MustCommit(db)
 		blockchain, _ = core.NewBlockChain(db, config, pow, evmux, vm.Config{})
 	)
-	pm, err := NewProtocolManager(config, false, DefaultConfig.NetworkId, 1000, evmux, new(testTxPool), pow, blockchain, db)
+	pm, err := NewProtocolManager(config, downloader.FullSync, DefaultConfig.NetworkId, 1000, evmux, new(testTxPool), pow, blockchain, db)
 	if err != nil {
 		t.Fatalf("failed to start test protocol manager: %v", err)
 	}
diff --git a/eth/helper_test.go b/eth/helper_test.go
index c0daa1b721..21ac3724ec 100644
--- a/eth/helper_test.go
+++ b/eth/helper_test.go
@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/p2p"
@@ -48,7 +49,7 @@ var (
 // newTestProtocolManager creates a new protocol manager for testing purposes,
 // with the given number of blocks already known, and potential notification
 // channels for different events.
-func newTestProtocolManager(fastSync bool, blocks int, generator func(int, *core.BlockGen), newtx chan<- []*types.Transaction) (*ProtocolManager, error) {
+func newTestProtocolManager(mode downloader.SyncMode, blocks int, generator func(int, *core.BlockGen), newtx chan<- []*types.Transaction) (*ProtocolManager, error) {
 	var (
 		evmux  = new(event.TypeMux)
 		engine = ethash.NewFaker()
@@ -65,7 +66,7 @@ func newTestProtocolManager(fastSync bool, blocks int, generator func(int, *core
 		panic(err)
 	}
 
-	pm, err := NewProtocolManager(gspec.Config, fastSync, DefaultConfig.NetworkId, 1000, evmux, &testTxPool{added: newtx}, engine, blockchain, db)
+	pm, err := NewProtocolManager(gspec.Config, mode, DefaultConfig.NetworkId, 1000, evmux, &testTxPool{added: newtx}, engine, blockchain, db)
 	if err != nil {
 		return nil, err
 	}
@@ -77,8 +78,8 @@ func newTestProtocolManager(fastSync bool, blocks int, generator func(int, *core
 // with the given number of blocks already known, and potential notification
 // channels for different events. In case of an error, the constructor force-
 // fails the test.
-func newTestProtocolManagerMust(t *testing.T, fastSync bool, blocks int, generator func(int, *core.BlockGen), newtx chan<- []*types.Transaction) *ProtocolManager {
-	pm, err := newTestProtocolManager(fastSync, blocks, generator, newtx)
+func newTestProtocolManagerMust(t *testing.T, mode downloader.SyncMode, blocks int, generator func(int, *core.BlockGen), newtx chan<- []*types.Transaction) *ProtocolManager {
+	pm, err := newTestProtocolManager(mode, blocks, generator, newtx)
 	if err != nil {
 		t.Fatalf("Failed to create protocol manager: %v", err)
 	}
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index fcc88fb0c6..74180bedd0 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -25,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/rlp"
 )
@@ -40,7 +41,7 @@ func TestStatusMsgErrors62(t *testing.T) { testStatusMsgErrors(t, 62) }
 func TestStatusMsgErrors63(t *testing.T) { testStatusMsgErrors(t, 63) }
 
 func testStatusMsgErrors(t *testing.T, protocol int) {
-	pm := newTestProtocolManagerMust(t, false, 0, nil, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, 0, nil, nil)
 	td, currentBlock, genesis := pm.blockchain.Status()
 	defer pm.Stop()
 
@@ -93,7 +94,7 @@ func TestRecvTransactions63(t *testing.T) { testRecvTransactions(t, 63) }
 
 func testRecvTransactions(t *testing.T, protocol int) {
 	txAdded := make(chan []*types.Transaction)
-	pm := newTestProtocolManagerMust(t, false, 0, nil, txAdded)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, 0, nil, txAdded)
 	pm.acceptTxs = 1 // mark synced to accept transactions
 	p, _ := newTestPeer("peer", protocol, pm, true)
 	defer pm.Stop()
@@ -120,7 +121,7 @@ func TestSendTransactions62(t *testing.T) { testSendTransactions(t, 62) }
 func TestSendTransactions63(t *testing.T) { testSendTransactions(t, 63) }
 
 func testSendTransactions(t *testing.T, protocol int) {
-	pm := newTestProtocolManagerMust(t, false, 0, nil, nil)
+	pm := newTestProtocolManagerMust(t, downloader.FullSync, 0, nil, nil)
 	defer pm.Stop()
 
 	// Fill the pool with big transactions.
diff --git a/eth/sync_test.go b/eth/sync_test.go
index 198ffaf272..9eaa1156fb 100644
--- a/eth/sync_test.go
+++ b/eth/sync_test.go
@@ -21,6 +21,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 )
@@ -29,12 +30,12 @@ import (
 // imported into the blockchain.
 func TestFastSyncDisabling(t *testing.T) {
 	// Create a pristine protocol manager, check that fast sync is left enabled
-	pmEmpty := newTestProtocolManagerMust(t, true, 0, nil, nil)
+	pmEmpty := newTestProtocolManagerMust(t, downloader.FastSync, 0, nil, nil)
 	if atomic.LoadUint32(&pmEmpty.fastSync) == 0 {
 		t.Fatalf("fast sync disabled on pristine blockchain")
 	}
 	// Create a full protocol manager, check that fast sync gets disabled
-	pmFull := newTestProtocolManagerMust(t, true, 1024, nil, nil)
+	pmFull := newTestProtocolManagerMust(t, downloader.FastSync, 1024, nil, nil)
 	if atomic.LoadUint32(&pmFull.fastSync) == 1 {
 		t.Fatalf("fast sync not disabled on non-empty blockchain")
 	}
diff --git a/les/backend.go b/les/backend.go
index 1c78ba846e..184464f207 100644
--- a/les/backend.go
+++ b/les/backend.go
@@ -104,7 +104,8 @@ func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
 	}
 
 	eth.txPool = light.NewTxPool(eth.chainConfig, eth.eventMux, eth.blockchain, eth.relay)
-	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.LightMode, config.NetworkId, eth.eventMux, eth.engine, eth.blockchain, nil, chainDb, odr, relay); err != nil {
+	lightSync := config.SyncMode == downloader.LightSync
+	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, lightSync, config.NetworkId, eth.eventMux, eth.engine, eth.blockchain, nil, chainDb, odr, relay); err != nil {
 		return nil, err
 	}
 	relay.ps = eth.protocolManager.peers
diff --git a/mobile/geth.go b/mobile/geth.go
index 0ecefb32bb..8ad931ccbe 100644
--- a/mobile/geth.go
+++ b/mobile/geth.go
@@ -22,12 +22,11 @@ package geth
 import (
 	"encoding/json"
 	"fmt"
-	"math/big"
 	"path/filepath"
 
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth"
-	"github.com/ethereum/go-ethereum/eth/gasprice"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/ethstats"
 	"github.com/ethereum/go-ethereum/les"
@@ -145,19 +144,13 @@ func NewNode(datadir string, config *NodeConfig) (stack *Node, _ error) {
 	}
 	// Register the Ethereum protocol if requested
 	if config.EthereumEnabled {
-		ethConf := &eth.Config{
-			Genesis:            genesis,
-			LightMode:          true,
-			DatabaseCache:      config.EthereumDatabaseCache,
-			NetworkId:          config.EthereumNetworkID,
-			GasPrice:           new(big.Int).SetUint64(20 * params.Shannon),
-			GPO:                gasprice.Config{Blocks: 10, Percentile: 50},
-			EthashCacheDir:     "ethash",
-			EthashCachesInMem:  2,
-			EthashCachesOnDisk: 3,
-		}
+		ethConf := eth.DefaultConfig
+		ethConf.Genesis = genesis
+		ethConf.SyncMode = downloader.LightSync
+		ethConf.NetworkId = config.EthereumNetworkID
+		ethConf.DatabaseCache = config.EthereumDatabaseCache
 		if err := rawStack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
-			return les.New(ctx, ethConf)
+			return les.New(ctx, &ethConf)
 		}); err != nil {
 			return nil, fmt.Errorf("ethereum init: %v", err)
 		}