diff --git a/consensus/consensus_msg_sender.go b/consensus/consensus_msg_sender.go
index 538cf5fc2..cb0198158 100644
--- a/consensus/consensus_msg_sender.go
+++ b/consensus/consensus_msg_sender.go
@@ -2,6 +2,7 @@ package consensus
 
 import (
 	"sync"
+	"sync/atomic"
 	"time"
 
 	msg_pb "github.com/harmony-one/harmony/api/proto/message"
@@ -18,7 +19,6 @@ const (
 // MessageSender is the wrapper object that controls how a consensus message is sent
 type MessageSender struct {
 	blockNum        uint64 // The current block number at consensus
-	blockNumMutex   sync.Mutex
 	messagesToRetry sync.Map
 	// The p2p host used to send/receive p2p messages
 	host p2p.Host
@@ -44,9 +44,7 @@ func NewMessageSender(host p2p.Host) *MessageSender {
 
 // Reset resets the sender's state for new block
 func (sender *MessageSender) Reset(blockNum uint64) {
-	sender.blockNumMutex.Lock()
-	sender.blockNum = blockNum
-	sender.blockNumMutex.Unlock()
+	atomic.StoreUint64(&sender.blockNum, blockNum)
 	sender.StopAllRetriesExceptCommitted()
 	sender.messagesToRetry.Range(func(key interface{}, value interface{}) bool {
 		if msgRetry, ok := value.(*MessageRetry); ok {
@@ -95,13 +93,11 @@ func (sender *MessageSender) Retry(msgRetry *MessageRetry) {
 		msgRetry.isActiveMutex.Unlock()
 
 		if msgRetry.msgType != msg_pb.MessageType_COMMITTED {
-			sender.blockNumMutex.Lock()
-			if msgRetry.blockNum < sender.blockNum {
-				sender.blockNumMutex.Unlock()
+			senderBlockNum := atomic.LoadUint64(&sender.blockNum)
+			if msgRetry.blockNum < senderBlockNum {
 				// Block already moved ahead, no need to retry old block's messages
 				return
 			}
-			sender.blockNumMutex.Unlock()
 		}
 
 		msgRetry.retryCount++