diff --git a/embed/templates/scripts/run_drainer.sh.tpl b/embed/templates/scripts/run_drainer.sh.tpl
index 2b5b7fca65..ce8a76bafa 100644
--- a/embed/templates/scripts/run_drainer.sh.tpl
+++ b/embed/templates/scripts/run_drainer.sh.tpl
@@ -30,4 +30,4 @@ exec bin/drainer \
     --data-dir="{{.DataDir}}" \
     --log-file="{{.LogDir}}/drainer.log" \
     --config=conf/drainer.toml \
-    --initial-commit-ts="{{.CommitTs}}" 2>> "{{.LogDir}}/drainer_stderr.log"
+    --initial-commit-ts={{.CommitTs}} 2>> "{{.LogDir}}/drainer_stderr.log"
diff --git a/pkg/cluster/spec/drainer.go b/pkg/cluster/spec/drainer.go
index 852ad63fa0..2f374cd696 100644
--- a/pkg/cluster/spec/drainer.go
+++ b/pkg/cluster/spec/drainer.go
@@ -38,7 +38,7 @@ type DrainerSpec struct {
 	DeployDir       string                 `yaml:"deploy_dir,omitempty"`
 	DataDir         string                 `yaml:"data_dir,omitempty"`
 	LogDir          string                 `yaml:"log_dir,omitempty"`
-	CommitTS        int64                  `yaml:"commit_ts,omitempty"`
+	CommitTS        int64                  `yaml:"commit_ts" default:"-1" validate:"commit_ts:editable"`
 	Offline         bool                   `yaml:"offline,omitempty"`
 	NumaNode        string                 `yaml:"numa_node,omitempty" validate:"numa_node:editable"`
 	Config          map[string]interface{} `yaml:"config,omitempty" validate:"config:ignore"`