diff --git a/index.d.ts b/index.d.ts
index effb0c1..6f4170d 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,5 +1,5 @@
 export default class WebpackAliOSSPlugin {
-  constructor(cfg: WebpackAliOSSPluginOptions)
+  constructor(cfg?: WebpackAliOSSPluginOptions)
 }
 
 export interface WebpackAliOSSPluginOptions {