diff --git a/pkg/cluster/ansible/service.go b/pkg/cluster/ansible/service.go
index b93b4a46a8..bd672da8b3 100644
--- a/pkg/cluster/ansible/service.go
+++ b/pkg/cluster/ansible/service.go
@@ -197,7 +197,7 @@ func parseDirs(ctx context.Context, user string, ins spec.InstanceSpec, sshTimeo
 				tsArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
 				tmpTs, _ := strconv.Atoi(strings.TrimPrefix(tsArg, "--initial-commit-ts="))
 				newIns.Config = make(map[string]interface{})
-				newIns.Config["initial_commit_ts"] = int64(tmpTs)
+				newIns.Config["initial-commit-ts"] = int64(tmpTs)
 			}
 		}
 		return newIns, nil
diff --git a/pkg/cluster/spec/spec.go b/pkg/cluster/spec/spec.go
index aec70a09cd..56ec4db237 100644
--- a/pkg/cluster/spec/spec.go
+++ b/pkg/cluster/spec/spec.go
@@ -870,16 +870,16 @@ func setHostArch(field reflect.Value, hostArch map[string]string) error {
 	return nil
 }
 
-// when upgrade form old tiup-cluster, replace spec.CommitTS with spec.Config["initial_commit_ts"]
+// when upgrade form old tiup-cluster, replace spec.CommitTS with spec.Config["initial-commit-ts"]
 func (s *Specification) removeCommitTS() {
-	_, ok1 := s.ServerConfigs.Drainer["initial_commit_ts"]
+	_, ok1 := s.ServerConfigs.Drainer["initial-commit-ts"]
 	for _, spec := range s.Drainers {
-		_, ok2 := spec.Config["initial_commit_ts"]
+		_, ok2 := spec.Config["initial-commit-ts"]
 		if !ok1 && !ok2 && spec.CommitTS != nil && *spec.CommitTS != -1 {
 			if spec.Config == nil {
 				spec.Config = make(map[string]interface{})
 			}
-			spec.Config["initial_commit_ts"] = *spec.CommitTS
+			spec.Config["initial-commit-ts"] = *spec.CommitTS
 		}
 		spec.CommitTS = nil
 	}