diff --git a/tools/pd-backup/pdbackup/backup.go b/tools/pd-backup/pdbackup/backup.go
index e3fd3e682cb..b9bc26aadf7 100644
--- a/tools/pd-backup/pdbackup/backup.go
+++ b/tools/pd-backup/pdbackup/backup.go
@@ -27,6 +27,7 @@ import (
 
 	clientv3 "go.etcd.io/etcd/client/v3"
 
+	"github.com/tikv/pd/pkg/mcs/utils/constant"
 	"github.com/tikv/pd/pkg/utils/etcdutil"
 	"github.com/tikv/pd/pkg/utils/keypath"
 	"github.com/tikv/pd/pkg/utils/typeutil"
@@ -76,7 +77,7 @@ func GetBackupInfo(client *clientv3.Client, pdAddr string) (*BackupInfo, error)
 
 	backInfo.AllocIDMax = allocIDMax
 
-	resp, err = etcdutil.EtcdKVGet(client, keypath.TimestampPath(rootPath))
+	resp, err = etcdutil.EtcdKVGet(client, keypath.TimestampPath(constant.DefaultKeyspaceGroupID))
 	if err != nil {
 		return nil, err
 	}
diff --git a/tools/pd-backup/pdbackup/backup_test.go b/tools/pd-backup/pdbackup/backup_test.go
index e6dc1e6345f..68a8f322a21 100644
--- a/tools/pd-backup/pdbackup/backup_test.go
+++ b/tools/pd-backup/pdbackup/backup_test.go
@@ -34,6 +34,7 @@ import (
 	"go.etcd.io/etcd/server/v3/embed"
 	"go.uber.org/goleak"
 
+	"github.com/tikv/pd/pkg/mcs/utils/constant"
 	sc "github.com/tikv/pd/pkg/schedule/config"
 	"github.com/tikv/pd/pkg/utils/etcdutil"
 	"github.com/tikv/pd/pkg/utils/keypath"
@@ -129,7 +130,7 @@ func (s *backupTestSuite) BeforeTest(string, string) {
 		rootPath               = path.Join(pdRootPath, strconv.FormatUint(clusterID, 10))
 		allocTimestampMaxBytes = typeutil.Uint64ToBytes(allocTimestampMax)
 	)
-	_, err = s.etcdClient.Put(ctx, keypath.TimestampPath(rootPath), string(allocTimestampMaxBytes))
+	_, err = s.etcdClient.Put(ctx, keypath.TimestampPath(constant.DefaultKeyspaceGroupID), string(allocTimestampMaxBytes))
 	re.NoError(err)
 
 	var (