diff --git a/envar.js b/envar.js
index 04c238b..b5b9944 100644
--- a/envar.js
+++ b/envar.js
@@ -73,7 +73,7 @@ module.exports = {
 
   /* 读取动态配置文件中的环境变量。
    */
-  get_dynamic_envar ({ dynamicEnvarFiles = './envar-base-dynamic.js' } = {}) {
+  get_dynamic_envar ({ dynamicEnvarFiles = ['./envar-base-dynamic.js'] } = {}) {
     // config file should be absolute or relative to the node process's dir.
 
     let dynamicEnvar = {}