diff --git a/Go/source/core/snowWorkerM1.go b/Go/source/core/snowWorkerM1.go
index 30a783c..b5fc7db 100644
--- a/Go/source/core/snowWorkerM1.go
+++ b/Go/source/core/snowWorkerM1.go
@@ -7,7 +7,6 @@
 package core
 
 import (
-	"math"
 	"sync"
 	"time"
 	"yitidgen/contract"
@@ -53,7 +52,7 @@ func NewSnowWorkerM1(options *contract.IdGeneratorOptions) contract.ISnowWorker
 	if options.MaxSeqNumber > 0 {
 		maxSeqNumber = options.MaxSeqNumber
 	} else {
-		maxSeqNumber = uint32(math.Pow(2, float64(options.SeqBitLength))) - 1
+		maxSeqNumber = (1 << seqBitLength) - 1
 	}
 	var minSeqNumber = options.MinSeqNumber
 	var topOverCostCount = options.TopOverCostCount
diff --git a/Go/source/core/snowWorkerM2.go b/Go/source/core/snowWorkerM2.go
index 7a08d01..48ebcd3 100644
--- a/Go/source/core/snowWorkerM2.go
+++ b/Go/source/core/snowWorkerM2.go
@@ -9,7 +9,6 @@ package core
 import (
 	"fmt"
 	"strconv"
-	"sync/atomic"
 	"yitidgen/contract"
 )
 
@@ -24,15 +23,17 @@ func NewSnowWorkerM2(options *contract.IdGeneratorOptions) contract.ISnowWorker
 }
 
 func (m2 SnowWorkerM2) NextId() uint64 {
+	m2.Lock()
+	defer m2.Unlock()
 	currentTimeTick := m2.GetCurrentTimeTick()
 	if m2._LastTimeTick == currentTimeTick {
-		atomic.AddUint32(&m2._CurrentSeqNumber, 1)
+		m2._CurrentSeqNumber++
 		if m2._CurrentSeqNumber > m2.MaxSeqNumber {
-			atomic.StoreUint32(&m2._CurrentSeqNumber, uint32(m2.MinSeqNumber))
+			m2._CurrentSeqNumber = m2.MinSeqNumber
 			currentTimeTick = m2.GetNextTimeTick()
 		}
 	} else {
-		atomic.StoreUint32(&m2._CurrentSeqNumber, uint32(m2.MinSeqNumber))
+		m2._CurrentSeqNumber = m2.MinSeqNumber
 	}
 	if currentTimeTick < m2._LastTimeTick {
 		fmt.Println("Time error for {0} milliseconds", strconv.FormatInt(m2._LastTimeTick-currentTimeTick, 10))