diff --git a/cmd/gost/program.go b/cmd/gost/program.go
index 9591485..1ad4ccd 100644
--- a/cmd/gost/program.go
+++ b/cmd/gost/program.go
@@ -152,8 +152,13 @@ func (p *program) Start() error {
 	cfg := config.Global()
 
 	if showConfig {
-		marshal, _ := yaml.Marshal(cfg)
-		fmt.Println(string(marshal))
+		if outputFormat == "json" {
+			marshal, _ := json.Marshal(cfg)
+			fmt.Println(string(marshal))
+		} else {
+			marshal, _ := yaml.Marshal(cfg)
+			fmt.Println(string(marshal))
+		}
 		os.Exit(0)
 		return nil
 	}