diff --git a/README.md b/README.md
index 691a206..f023ed9 100644
--- a/README.md
+++ b/README.md
@@ -74,7 +74,8 @@ These steps are executed in runner-images. We use `sudo -u tt` to elevate the pe
 
 1. Run JOJ3
    1. Parse the message.
-       - If not specified by `-msg`, it will use the git commit message from `HEAD`. The message should meet the [Conventional Commits specification](https://www.conventionalcommits.org/). We use `scope` and `description` here.
+       - It will use the git commit message from `HEAD`. The message should meet the [Conventional Commits specification](https://www.conventionalcommits.org/). We use `scope` and `description` here.
+       - If `-tag` is specified, then it should equal to the scope of the message, or JOJ3 will not run.
    2. Find the configuration file.
        - We have `conf-root` and `conf-name` specified in the CLI argument. Then the full path of configuration file is `<conf-root>/<scope>/<conf-name>`.
    3. Generate stages.
diff --git a/cmd/joj3/main.go b/cmd/joj3/main.go
index 0b9ada8..57bc0c1 100644
--- a/cmd/joj3/main.go
+++ b/cmd/joj3/main.go
@@ -14,7 +14,6 @@ import (
 var (
 	confRoot    string
 	confName    string
-	msg         string
 	tag         string
 	showVersion *bool
 	Version     string = "debug"
@@ -23,7 +22,6 @@ var (
 func init() {
 	flag.StringVar(&confRoot, "conf-root", ".", "root path for all config files")
 	flag.StringVar(&confName, "conf-name", "conf.json", "filename for config files")
-	flag.StringVar(&msg, "msg", "", "message to trigger the running, leave empty to use git commit message on HEAD")
 	flag.StringVar(&tag, "tag", "", "tag to trigger the running, when non-empty, should equal to the scope in msg")
 	showVersion = flag.Bool("version", false, "print current version")
 }
@@ -39,13 +37,10 @@ func mainImpl() error {
 		return nil
 	}
 	slog.Info("start joj3", "version", Version)
-	if msg == "" {
-		var err error
-		msg, err = conf.GetCommitMsg()
-		if err != nil {
-			slog.Error("get commit msg", "error", err)
-			return err
-		}
+	msg, err := conf.GetCommitMsg()
+	if err != nil {
+		slog.Error("get commit msg", "error", err)
+		return err
 	}
 	confPath, group, err := conf.ParseMsg(confRoot, confName, msg, tag)
 	if err != nil {