diff --git a/eth/backend.go b/eth/backend.go
index 52ec40f5ae..a5a9a186cf 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -411,6 +411,10 @@ func (s *Ethereum) SetEtherbase(etherbase common.Address) {
 // is already running, this method adjust the number of threads allowed to use
 // and updates the minimum price required by the transaction pool.
 func (s *Ethereum) StartMining(threads int) error {
+	// Reject mining request if the node is not synced.
+	if atomic.LoadUint32(&s.protocolManager.synced) == 0 {
+		return errors.New("node is not synced")
+	}
 	// Update the thread count within the consensus engine
 	type threaded interface {
 		SetThreads(threads int)
@@ -444,10 +448,6 @@ func (s *Ethereum) StartMining(threads int) error {
 			}
 			clique.Authorize(eb, wallet.SignData)
 		}
-		// If mining is started, we can disable the transaction rejection mechanism
-		// introduced to speed sync times.
-		atomic.StoreUint32(&s.protocolManager.acceptTxs, 1)
-
 		go s.miner.Start(eb)
 	}
 	return nil
@@ -480,7 +480,7 @@ func (s *Ethereum) IsListening() bool                  { return true } // Always
 func (s *Ethereum) EthVersion() int                    { return int(s.protocolManager.SubProtocols[0].Version) }
 func (s *Ethereum) NetVersion() uint64                 { return s.networkID }
 func (s *Ethereum) Downloader() *downloader.Downloader { return s.protocolManager.downloader }
-func (s *Ethereum) Synced() bool                       { return atomic.LoadUint32(&s.protocolManager.acceptTxs) == 1 }
+func (s *Ethereum) Synced() bool                       { return atomic.LoadUint32(&s.protocolManager.synced) == 1 }
 func (s *Ethereum) ArchiveMode() bool                  { return s.config.NoPruning }
 
 // Protocols implements node.Service, returning all the currently configured
diff --git a/eth/handler.go b/eth/handler.go
index 58add2eafc..3aa7e65b68 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -69,8 +69,8 @@ func errResp(code errCode, format string, v ...interface{}) error {
 type ProtocolManager struct {
 	networkID uint64
 
-	fastSync  uint32 // Flag whether fast sync is enabled (gets disabled if we already have blocks)
-	acceptTxs uint32 // Flag whether we're considered synchronised (enables transaction processing)
+	fastSync uint32 // Flag whether fast sync is enabled (gets disabled if we already have blocks)
+	synced   uint32 // Flag whether we're considered synchronised (enables transaction processing)
 
 	checkpointNumber uint64      // Block number for the sync progress validator to cross reference
 	checkpointHash   common.Hash // Block hash for the sync progress validator to cross reference
@@ -207,7 +207,7 @@ func NewProtocolManager(config *params.ChainConfig, mode downloader.SyncMode, ne
 		}
 		n, err := manager.blockchain.InsertChain(blocks)
 		if err == nil {
-			atomic.StoreUint32(&manager.acceptTxs, 1) // Mark initial sync done on any fetcher import
+			atomic.StoreUint32(&manager.synced, 1) // Mark initial sync done on any fetcher import
 		}
 		return n, err
 	}
@@ -706,7 +706,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 
 	case msg.Code == TxMsg:
 		// Transactions arrived, make sure we have a valid and fresh chain to handle them
-		if atomic.LoadUint32(&pm.acceptTxs) == 0 {
+		if atomic.LoadUint32(&pm.synced) == 0 {
 			break
 		}
 		// Transactions can be processed, parse all of them and deliver to the pool
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index e817d673a6..4abf905520 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -99,7 +99,7 @@ func TestRecvTransactions63(t *testing.T) { testRecvTransactions(t, 63) }
 func testRecvTransactions(t *testing.T, protocol int) {
 	txAdded := make(chan []*types.Transaction)
 	pm, _ := newTestProtocolManagerMust(t, downloader.FullSync, 0, nil, txAdded)
-	pm.acceptTxs = 1 // mark synced to accept transactions
+	pm.synced = 1 // mark synced to accept transactions
 	p, _ := newTestPeer("peer", protocol, pm, true)
 	defer pm.Stop()
 	defer p.close()
diff --git a/eth/sync.go b/eth/sync.go
index e303ef8d4e..897bc223dd 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -209,7 +209,7 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 		// Checkpoint passed, sanity check the timestamp to have a fallback mechanism
 		// for non-checkpointed (number = 0) private networks.
 		if head.Time() >= uint64(time.Now().AddDate(0, -1, 0).Unix()) {
-			atomic.StoreUint32(&pm.acceptTxs, 1)
+			atomic.StoreUint32(&pm.synced, 1)
 		}
 	}
 	if head.NumberU64() > 0 {