diff --git a/packages/fes-preset-built-in/src/utils/generateFiles.js b/packages/fes-preset-built-in/src/utils/generateFiles.js
index d0db197d..ddc0534f 100644
--- a/packages/fes-preset-built-in/src/utils/generateFiles.js
+++ b/packages/fes-preset-built-in/src/utils/generateFiles.js
@@ -12,7 +12,7 @@ export default async ({ api, watch }) => {
         });
     }
 
-    const watchers = [];
+    let watchers = [];
 
     await generate();