diff --git a/app/port/controller/PackageVersionFileController.ts b/app/port/controller/PackageVersionFileController.ts
index 60316bab0..6e9180867 100644
--- a/app/port/controller/PackageVersionFileController.ts
+++ b/app/port/controller/PackageVersionFileController.ts
@@ -152,7 +152,9 @@ export class PackageVersionFileController extends AbstractController {
 
       if (possibleFile) {
         const route = `/${fullname}/${versionSpec}/files${possibleFile.path}${hasMeta ? '?meta' : ''}`;
+
         ctx.redirect(route);
+
         return;
       }
 
@@ -174,21 +176,19 @@ export class PackageVersionFileController extends AbstractController {
   /**
    * compatibility with unpkg
    * 1. try to match alias entry. e.g. accessing `index.js` or `index.json` using /index
-   * 2. if given path is directory and has `index.js` file, redirect to it. e.g. using `lib` alias to access `lib/index.js`
-   * @param packageVersion
-   * @param path
-   * @return
+   * 2. if given path is directory and has `index.js` file, redirect to it. e.g. using `lib` alias to access `lib/index.js` or `lib/index.json`
+   * @param {PackageVersion} packageVersion packageVersion
+   * @param {String} path  filepath
+   * @return {Promise<PackageVersionFile | undefined>} return packageVersionFile or null
    */
-  async #searchPossibleEntries(packageVersion: any, path: string) {
-    const possiblePath = [ `${path}.js`, `${path}.json`, `${path}/index.js` ];
+  async #searchPossibleEntries(packageVersion: PackageVersion, path: string) {
+    const possiblePath = [ `${path}.js`, `${path}.json`, `${path}/index.js`, `${path}/index.json` ];
 
-    const possibleFiles = possiblePath.map(pathItem => this.packageVersionFileService.showPackageVersionFile(packageVersion, pathItem));
+    for (const pathItem of possiblePath) {
+      const file = await this.packageVersionFileService.showPackageVersionFile(packageVersion, pathItem);
 
-    const files = await Promise.allSettled(possibleFiles);
-
-    for (const file of files) {
-      if (file.status === 'fulfilled' && file.value) {
-        return file.value;
+      if (file) {
+        return file;
       }
     }
   }