diff --git a/background.js b/background.js
index 5899a4f..e3e230e 100644
--- a/background.js
+++ b/background.js
@@ -1,22 +1,17 @@
-let wechatHeaders = {
+const wechatHeaders = {
   extspam:
     "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",
   "client-version": "2.0.0",
 };
 
-let wechatUrls = ["https://wx.qq.com/*", "https://web.wechat.com/*", "https://wx2.qq.com/*", "https://wx8.qq.com/*"];
+const wechatUrls = ["https://wx.qq.com/*", "https://web.wechat.com/*", "https://wx2.qq.com/*", "https://wx8.qq.com/*"];
 
 chrome.webRequest.onBeforeRequest.addListener(
   function (details) {
-    let url = new URL(details.url);
-    if (url.pathname == "/" && url.search.indexOf("target=t") == -1) {
-      if (url.search == "" || url.search == "?") {
-        url.search = "?";
-      } else {
-        url.search += "&";
-      }
-      url.search += "target=t";
-      return { redirectUrl: url.href };
+    const url = new URL(details.url);
+    if (url.searchParams.get("target") !== 't') {
+		url.searchParams.set("target", 't');
+		return { redirectUrl: url.href };
     }
     return {};
   },
@@ -26,7 +21,7 @@ chrome.webRequest.onBeforeRequest.addListener(
 
 chrome.webRequest.onBeforeSendHeaders.addListener(
   function (details) {
-    let url = new URL(details.url);
+    const url = new URL(details.url);
     if (url.pathname == "/cgi-bin/mmwebwx-bin/webwxnewloginpage") {
       for (var k in wechatHeaders) {
         details.requestHeaders.push({