diff --git a/miner/agent.go b/miner/agent.go
index 4f1ea3f65c..beaf30556a 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -18,10 +18,10 @@ package miner
 
 import (
 	"sync"
+	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/log"
-	"sync/atomic"
 )
 
 type CpuAgent struct {
diff --git a/miner/miner.go b/miner/miner.go
index 0da233dd74..e7add025de 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -114,7 +114,6 @@ func (self *Miner) Start(coinbase common.Address) {
 	}
 	if !self.worker.isRunning() {
 		self.worker.start()
-		self.worker.commitNewWork()
 	}
 }
 
diff --git a/miner/worker.go b/miner/worker.go
index 1dcf2c9b1e..ba39cb83dd 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -251,6 +251,11 @@ func (self *worker) update() {
 	defer self.chainHeadSub.Unsubscribe()
 	defer self.chainSideSub.Unsubscribe()
 
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
+
+	var started bool // Indication whether consensus engine is started
+
 	for {
 		// A real event arrived, process interesting content
 		select {
@@ -289,6 +294,17 @@ func (self *worker) update() {
 				}
 			}
 
+		// Commit new work when consensus engine is started.
+		case <-ticker.C:
+			if self.engine.IsRunning() {
+				if !started {
+					self.commitNewWork()
+					started = true
+				}
+			} else {
+				started = false
+			}
+
 		// System stopped
 		case <-self.txsSub.Err():
 			return