diff --git a/cmd/cconfig/migrate_task.go b/cmd/cconfig/migrate_task.go
index 89da538cb..eb887978d 100644
--- a/cmd/cconfig/migrate_task.go
+++ b/cmd/cconfig/migrate_task.go
@@ -139,6 +139,7 @@ func (t *MigrateTask) run() error {
 	if err != nil {
 		log.ErrorErrorf(err, "migrate single slot failed")
 		t.UpdateStatus(MIGRATE_TASK_ERR)
+		t.rollbackPremigrate()
 		return err
 	}
 	t.UpdateFinish()
@@ -146,6 +147,18 @@ func (t *MigrateTask) run() error {
 	return nil
 }
 
+func (t *MigrateTask) rollbackPremigrate() {
+	if s, err := models.GetSlot(t.zkConn, t.productName, t.SlotId); err == nil && s.State.Status == models.SLOT_STATUS_PRE_MIGRATE {
+		s.State.Status = models.SLOT_STATUS_ONLINE
+		err = s.Update(t.zkConn)
+		if err != nil {
+			log.Warn("rollback premigrate failed", err)
+		} else {
+			log.Infof("rollback slot %d from premigrate to online\n", s.Id)
+		}
+	}
+}
+
 var ErrGroupMasterNotFound = errors.New("group master not found")
 
 // will block until all keys are migrated
diff --git a/pkg/models/proxy.go b/pkg/models/proxy.go
index c239e2aef..875110efb 100644
--- a/pkg/models/proxy.go
+++ b/pkg/models/proxy.go
@@ -160,7 +160,7 @@ func SetProxyStatus(zkConn zkhelper.Conn, productName string, proxyName string,
 			return errors.Trace(err)
 		}
 		for _, slot := range slots {
-			if slot.State.Status != SLOT_STATUS_ONLINE && slot.State.Status != SLOT_STATUS_MIGRATE{
+			if slot.State.Status != SLOT_STATUS_ONLINE && slot.State.Status != SLOT_STATUS_MIGRATE {
 				return errors.Errorf("slot %v is not online or migrate", slot)
 			}
 			if slot.GroupId == INVALID_ID {
diff --git a/pkg/models/server_group.go b/pkg/models/server_group.go
index 697049306..b6a16ed55 100644
--- a/pkg/models/server_group.go
+++ b/pkg/models/server_group.go
@@ -153,7 +153,7 @@ func (self *ServerGroup) Remove(zkConn zkhelper.Conn) error {
 		if slot.GroupId == self.Id {
 			return errors.Errorf("group %d is using by slot %d", slot.GroupId, slot.Id)
 		}
-		if ((slot.State.Status == SLOT_STATUS_MIGRATE || slot.State.Status == SLOT_STATUS_PRE_MIGRATE) && slot.State.MigrateStatus.From == self.Id) {
+		if (slot.State.Status == SLOT_STATUS_MIGRATE || slot.State.Status == SLOT_STATUS_PRE_MIGRATE) && slot.State.MigrateStatus.From == self.Id {
 			return errors.Errorf("slot %d has residual data remain in group %d", slot.Id, self.Id)
 		}
 	}