diff --git a/cmd/containerd/command/main.go b/cmd/containerd/command/main.go
index 922b54f8f..3b8e9739e 100644
--- a/cmd/containerd/command/main.go
+++ b/cmd/containerd/command/main.go
@@ -357,7 +357,7 @@ func setLogLevel(context *cli.Context, config *srvconfig.Config) error {
 }
 
 func setLogFormat(config *srvconfig.Config) error {
-	f := config.Debug.Format
+	f := log.OutputFormat(config.Debug.Format)
 	if f == "" {
 		f = log.TextFormat
 	}
diff --git a/log/context.go b/log/context.go
index a6075a8ce..57aac5c7d 100644
--- a/log/context.go
+++ b/log/context.go
@@ -96,17 +96,20 @@ func GetLevel() Level {
 	return logrus.GetLevel()
 }
 
+// OutputFormat specifies a log output format.
+type OutputFormat string
+
 // Supported log output formats.
 const (
 	// TextFormat represents the text logging format.
-	TextFormat = "text"
+	TextFormat OutputFormat = "text"
 
 	// JSONFormat represents the JSON logging format.
-	JSONFormat = "json"
+	JSONFormat OutputFormat = "json"
 )
 
 // SetFormat sets the log output format ([TextFormat] or [JSONFormat]).
-func SetFormat(format string) error {
+func SetFormat(format OutputFormat) error {
 	switch format {
 	case TextFormat:
 		logrus.SetFormatter(&logrus.TextFormatter{