diff --git a/go/base/context.go b/go/base/context.go
index cc8e9cc..3757653 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -178,7 +178,8 @@ type MigrationContext struct {
 	RenameTablesEndTime                    time.Time
 	pointOfInterestTime                    time.Time
 	pointOfInterestTimeMutex               *sync.Mutex
-	CurrentHeartbeatLag                    int64
+	lastHeartbeatOnChangelogTime           time.Time
+	lastHeartbeatOnChangelogMutex          *sync.Mutex
 	CurrentLag                             int64
 	currentProgress                        uint64
 	ThrottleHTTPStatusCode                 int64
@@ -272,6 +273,7 @@ func NewMigrationContext() *MigrationContext {
 		throttleControlReplicaKeys:          mysql.NewInstanceKeyMap(),
 		configMutex:                         &sync.Mutex{},
 		pointOfInterestTimeMutex:            &sync.Mutex{},
+		lastHeartbeatOnChangelogMutex:       &sync.Mutex{},
 		ColumnRenameMap:                     make(map[string]string),
 		PanicAbort:                          make(chan error),
 		Log:                                 NewDefaultLogger(),
@@ -455,8 +457,8 @@ func (this *MigrationContext) MarkRowCopyEndTime() {
 	this.RowCopyEndTime = time.Now()
 }
 
-func (this *MigrationContext) GetCurrentHeartbeatLagDuration() time.Duration {
-	return time.Duration(atomic.LoadInt64(&this.CurrentHeartbeatLag))
+func (this *MigrationContext) TimeSinceLastHeartbeatOnChangelog() time.Duration {
+	return time.Since(this.GetLastHeartbeatOnChangelogTime())
 }
 
 func (this *MigrationContext) GetCurrentLagDuration() time.Duration {
@@ -498,6 +500,20 @@ func (this *MigrationContext) TimeSincePointOfInterest() time.Duration {
 	return time.Since(this.pointOfInterestTime)
 }
 
+func (this *MigrationContext) SetLastHeartbeatOnChangelogTime(t time.Time) {
+	this.lastHeartbeatOnChangelogMutex.Lock()
+	defer this.lastHeartbeatOnChangelogMutex.Unlock()
+
+	this.lastHeartbeatOnChangelogTime = t
+}
+
+func (this *MigrationContext) GetLastHeartbeatOnChangelogTime() time.Time {
+	this.lastHeartbeatOnChangelogMutex.Lock()
+	defer this.lastHeartbeatOnChangelogMutex.Unlock()
+
+	return this.lastHeartbeatOnChangelogTime
+}
+
 func (this *MigrationContext) SetHeartbeatIntervalMilliseconds(heartbeatIntervalMilliseconds int64) {
 	if heartbeatIntervalMilliseconds < 100 {
 		heartbeatIntervalMilliseconds = 100
diff --git a/go/logic/hooks.go b/go/logic/hooks.go
index 9f119be..71f070c 100644
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@@ -64,7 +64,7 @@ func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) [
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_HOST=%s", this.migrationContext.GetInspectorHostname()))
 	env = append(env, fmt.Sprintf("GH_OST_EXECUTING_HOST=%s", this.migrationContext.Hostname))
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_LAG=%f", this.migrationContext.GetCurrentLagDuration().Seconds()))
-	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.GetCurrentHeartbeatLagDuration().Seconds()))
+	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_PROGRESS=%f", this.migrationContext.GetProgressPct()))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT=%s", this.migrationContext.HooksHintMessage))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_OWNER=%s", this.migrationContext.HooksHintOwner))
diff --git a/go/logic/migrator.go b/go/logic/migrator.go
index 2c95e63..5bc6997 100644
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@@ -255,10 +255,12 @@ func (this *Migrator) onChangelogStateEvent(dmlEvent *binlog.BinlogDMLEvent) (er
 
 func (this *Migrator) onChangelogHeartbeatEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
 	changelogHeartbeatString := dmlEvent.NewColumnValues.StringColumn(3)
-	if lag, err := parseChangelogHeartbeat(changelogHeartbeatString); err != nil {
+
+	heartbeatTime, err := time.Parse(time.RFC3339Nano, changelogHeartbeatString)
+	if err != nil {
 		return this.migrationContext.Log.Errore(err)
 	} else {
-		atomic.StoreInt64(&this.migrationContext.CurrentHeartbeatLag, int64(lag))
+		this.migrationContext.SetLastHeartbeatOnChangelogTime(heartbeatTime)
 		return nil
 	}
 }
@@ -521,10 +523,10 @@ func (this *Migrator) cutOver() (err error) {
 	this.migrationContext.Log.Infof("Waiting for heartbeat lag to be low enough to proceed")
 	this.sleepWhileTrue(
 		func() (bool, error) {
-			currentHeartbeatLag := atomic.LoadInt64(&this.migrationContext.CurrentHeartbeatLag)
+			heartbeatLag := this.migrationContext.TimeSinceLastHeartbeatOnChangelog()
 			maxLagMillisecondsThrottleThreshold := atomic.LoadInt64(&this.migrationContext.MaxLagMillisecondsThrottleThreshold)
-			if time.Duration(currentHeartbeatLag) > time.Duration(maxLagMillisecondsThrottleThreshold)*time.Millisecond {
-				this.migrationContext.Log.Debugf("current HeartbeatLag (%.2fs) is too high, it needs to be less than --max-lag-millis (%.2fs) to continue", time.Duration(currentHeartbeatLag).Seconds(), (time.Duration(maxLagMillisecondsThrottleThreshold) * time.Millisecond).Seconds())
+			if heartbeatLag > time.Duration(maxLagMillisecondsThrottleThreshold)*time.Millisecond {
+				this.migrationContext.Log.Infof("current HeartbeatLag (%.2fs) is too high, it needs to be less than --max-lag-millis (%.2fs) to continue", heartbeatLag.Seconds(), (time.Duration(maxLagMillisecondsThrottleThreshold) * time.Millisecond).Seconds())
 				return true, nil
 			} else {
 				return false, nil
@@ -1003,7 +1005,7 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 		base.PrettifyDurationOutput(elapsedTime), base.PrettifyDurationOutput(this.migrationContext.ElapsedRowCopyTime()),
 		currentBinlogCoordinates,
 		this.migrationContext.GetCurrentLagDuration().Seconds(),
-		this.migrationContext.GetCurrentHeartbeatLagDuration().Seconds(),
+		this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds(),
 		state,
 		eta,
 	)