diff --git a/package.json b/package.json
index ec91ef35..0bd93503 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,7 @@
 {
   "name": "@easyops-cn/docusaurus-search-local",
   "version": "0.9.3",
+  "description": "An offline/local search plugin for Docusaurus v2.",
   "repository": "https://github.com/easyops-cn/docusaurus-search-local",
   "homepage": "https://github.com/easyops-cn/docusaurus-search-local",
   "scripts": {
diff --git a/src/server/utils/getIndexHash.spec.ts b/src/server/utils/getIndexHash.spec.ts
index 6f1273b5..ee4478fe 100644
--- a/src/server/utils/getIndexHash.spec.ts
+++ b/src/server/utils/getIndexHash.spec.ts
@@ -9,6 +9,16 @@ const mockConsoleWarn = jest
   .spyOn(console, "warn")
   .mockImplementation(() => void 0);
 
+jest.mock(
+  "../../../../package.json",
+  () => ({
+    version: "0.0.0",
+  }),
+  {
+    virtual: true,
+  }
+);
+
 (klawSync as jest.MockedFunction<typeof klawSync>).mockImplementation(
   (root, options) => {
     let files: string[] = [];
@@ -47,7 +57,7 @@ const mockConsoleWarn = jest
 describe("getIndexHash", () => {
   test.each<[Partial<ProcessedPluginOptions>, string | null, number]>([
     [{ hashed: false }, null, 0],
-    [{ hashed: true, indexDocs: true, docsDir: "/tmp/docs" }, "a387bd69", 0],
+    [{ hashed: true, indexDocs: true, docsDir: "/tmp/docs" }, "87def35c", 0],
     [{ hashed: true, indexBlog: true, blogDir: "/tmp/blog" }, null, 0],
     [
       { hashed: true, indexDocs: true, docsDir: "/does-not-exist/docs" },
diff --git a/src/server/utils/getIndexHash.ts b/src/server/utils/getIndexHash.ts
index 26d9d88b..4a1b5340 100644
--- a/src/server/utils/getIndexHash.ts
+++ b/src/server/utils/getIndexHash.ts
@@ -1,7 +1,9 @@
 import fs from "fs";
+import path from "path";
 import crypto from "crypto";
 import klawSync from "klaw-sync";
 import { ProcessedPluginOptions } from "../../shared/interfaces";
+import { debugInfo } from "./debug";
 
 export function getIndexHash(config: ProcessedPluginOptions): string | null {
   if (!config.hashed) {
@@ -35,10 +37,25 @@ export function getIndexHash(config: ProcessedPluginOptions): string | null {
 
   if (files.length > 0) {
     const md5sum = crypto.createHash("md5");
+
+    // The version of this plugin should be counted in hash,
+    // since the index maybe changed between versions.
+
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const pluginVersion = require(path.resolve(
+      __dirname,
+      "../../../../package.json"
+    )).version;
+    debugInfo("using @easyops-cn/docusaurus-search-local v%s", pluginVersion);
+    md5sum.update(pluginVersion, "utf8");
+
     for (const item of files) {
       md5sum.update(fs.readFileSync(item.path));
     }
-    return md5sum.digest("hex").substring(0, 8);
+
+    const indexHash = md5sum.digest("hex").substring(0, 8);
+    debugInfo("the index hash is %j", indexHash);
+    return indexHash;
   }
   return null;
 }