diff --git a/util.go b/util.go
index f509f65..cb2ad98 100644
--- a/util.go
+++ b/util.go
@@ -187,7 +187,7 @@ func marshal(target interface{}, ext string) ([]byte, error) {
 		}
 		return buf.Bytes(), nil
 	case ".json":
-		return json.Marshal(target)
+		return json.MarshalIndent(target, "", "\t")
 	default:
 		return nil, fmt.Errorf("Config: Not supported extention[%s]", ext)
 	}