diff --git a/protocol/syncer.go b/protocol/syncer.go
index 258baebbd9..214655e587 100644
--- a/protocol/syncer.go
+++ b/protocol/syncer.go
@@ -295,15 +295,20 @@ func (s *Syncer) updatePeerStatus(peerID peer.ID, status *Status) {
 
 // Broadcast broadcasts a block to all peers
 func (s *Syncer) Broadcast(b *types.Block) {
-	// diff is number in ibft
-	diff := new(big.Int).SetUint64(b.Header.Difficulty)
+	// Get the chain difficulty associated with block
+	td, ok := s.blockchain.GetTD(b.Hash())
+	if !ok {
+		// not supposed to happen
+		s.logger.Error("total difficulty not found", "block number", b.Number())
+		return
+	}
 
 	// broadcast the new block to all the peers
 	req := &proto.NotifyReq{
 		Status: &proto.V1Status{
 			Hash:       b.Hash().String(),
 			Number:     b.Number(),
-			Difficulty: diff.String(),
+			Difficulty: td.String(),
 		},
 		Raw: &any.Any{
 			Value: b.MarshalRLP(),
@@ -385,7 +390,6 @@ func (s *Syncer) BestPeer() *syncPeer {
 	}
 
 	curDiff := s.blockchain.CurrentTD()
-
 	if bestTd.Cmp(curDiff) <= 0 {
 		return nil
 	}
diff --git a/protocol/syncer_test.go b/protocol/syncer_test.go
index 5bca90f760..7f589f89f1 100644
--- a/protocol/syncer_test.go
+++ b/protocol/syncer_test.go
@@ -93,25 +93,29 @@ func TestDeletePeer(t *testing.T) {
 
 func TestBroadcast(t *testing.T) {
 	tests := []struct {
-		name         string
-		chain        blockchainShim
-		peerChain    blockchainShim
-		numNewBlocks int
+		name          string
+		syncerHeaders []*types.Header
+		peerHeaders   []*types.Header
+		numNewBlocks  int
 	}{
 		{
-			name:         "syncer should receive new block in peer",
-			chain:        NewRandomChain(t, 5),
-			peerChain:    NewRandomChain(t, 10),
-			numNewBlocks: 5,
+			name:          "syncer should receive new block in peer",
+			syncerHeaders: blockchain.NewTestHeaderChainWithSeed(nil, 5, 0),
+			peerHeaders:   blockchain.NewTestHeaderChainWithSeed(nil, 10, 0),
+			numNewBlocks:  5,
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			syncer, peerSyncers := SetupSyncerNetwork(t, tt.chain, []blockchainShim{tt.peerChain})
+			chain, peerChain := NewMockBlockchain(tt.syncerHeaders), NewMockBlockchain(tt.peerHeaders)
+			syncer, peerSyncers := SetupSyncerNetwork(t, chain, []blockchainShim{peerChain})
 			peerSyncer := peerSyncers[0]
 
 			newBlocks := GenerateNewBlocks(t, peerSyncer.blockchain, tt.numNewBlocks)
+
+			assert.NoError(t, peerSyncer.blockchain.WriteBlocks(newBlocks))
+
 			for _, newBlock := range newBlocks {
 				peerSyncer.Broadcast(newBlock)
 			}
@@ -271,6 +275,9 @@ func TestWatchSyncWithPeer(t *testing.T) {
 			peerSyncer := peerSyncers[0]
 
 			newBlocks := GenerateNewBlocks(t, peerChain, tt.numNewBlocks)
+
+			assert.NoError(t, peerSyncer.blockchain.WriteBlocks(newBlocks))
+
 			for _, b := range newBlocks {
 				peerSyncer.Broadcast(b)
 			}
diff --git a/protocol/testing.go b/protocol/testing.go
index 7d79442513..b08df1e75d 100644
--- a/protocol/testing.go
+++ b/protocol/testing.go
@@ -115,7 +115,7 @@ func SetupSyncerNetwork(t *testing.T, chain blockchainShim, peerChains []blockch
 		network.MultiJoin(t, syncer.server, peerSyncers[idx].server)
 	}
 	WaitUntilPeerConnected(t, syncer, len(peerChains), 10*time.Second)
-	return
+	return syncer, peerSyncers
 }
 
 // GenerateNewBlocks returns new blocks from latest block of given chain
@@ -166,10 +166,14 @@ func GetCurrentStatus(b blockchainShim) *Status {
 
 // HeaderToStatus converts given header to Status
 func HeaderToStatus(h *types.Header) *Status {
+	var td uint64 = 0
+	for i := uint64(1); i <= h.Difficulty; i++ {
+		td = td + i
+	}
 	return &Status{
 		Hash:       h.Hash,
 		Number:     h.Number,
-		Difficulty: big.NewInt(0).SetUint64(h.Difficulty),
+		Difficulty: big.NewInt(0).SetUint64(td),
 	}
 }
 
@@ -207,13 +211,18 @@ func (b *mockBlockchain) CurrentTD() *big.Int {
 	if current == nil {
 		return nil
 	}
-	return new(big.Int).SetUint64(current.Difficulty)
+
+	td, _ := b.GetTD(current.Hash)
+	return td
 }
 
 func (b *mockBlockchain) GetTD(hash types.Hash) (*big.Int, bool) {
+	var td uint64 = 0
 	for _, b := range b.blocks {
+		td = td + b.Header.Difficulty
+
 		if b.Header.Hash == hash {
-			return new(big.Int).SetUint64(b.Header.Difficulty), true
+			return big.NewInt(0).SetUint64(td), true
 		}
 	}
 	return nil, false
@@ -264,8 +273,9 @@ func NewMockSubscription() *mockSubscription {
 
 func (s *mockSubscription) AppendBlocks(blocks []*types.Block) {
 	for _, b := range blocks {
+		status := HeaderToStatus(b.Header)
 		s.eventCh <- &blockchain.Event{
-			Difficulty: new(big.Int).SetUint64(b.Header.Difficulty),
+			Difficulty: status.Difficulty,
 			NewChain:   []*types.Header{b.Header},
 		}
 	}