diff --git a/package-lock.json b/package-lock.json
index 1e25582..f5226a6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,7 @@
         "core-js": "^3.8.3",
         "highlight.js": "^10.7.3",
         "jszip": "^3.10.1",
-        "lib-iitc-manager": "^1.8.4",
+        "lib-iitc-manager": "^1.9.0",
         "scored-fuzzysearch": "^1.0.5",
         "vue": "^2.6.14"
       },
@@ -9460,9 +9460,9 @@
       }
     },
     "node_modules/lib-iitc-manager": {
-      "version": "1.8.4",
-      "resolved": "https://registry.npmjs.org/lib-iitc-manager/-/lib-iitc-manager-1.8.4.tgz",
-      "integrity": "sha512-1Mk58EgTbUDR7DOZAqx8oEWaFvu8kuhyZPyyuAIYYDf91jAdr61Ht3/rtQYOSXPIQGTj+sbgN5musk40puverQ==",
+      "version": "1.9.0",
+      "resolved": "https://registry.npmjs.org/lib-iitc-manager/-/lib-iitc-manager-1.9.0.tgz",
+      "integrity": "sha512-8baF0kySzDQIqNv8+eSLNhjHN+jQIG8TLKvENDNVSaE4dWmdyF0IjWaYqxxE06+uwQktQG3XeY49QLYelmBscw==",
       "dependencies": {
         "@bundled-es-modules/deepmerge": "^4.3.1",
         "xhr2": "^0.2.1"
diff --git a/package.json b/package.json
index aabc2ec..4ae80ed 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
     "core-js": "^3.8.3",
     "highlight.js": "^10.7.3",
     "jszip": "^3.10.1",
-    "lib-iitc-manager": "^1.8.4",
+    "lib-iitc-manager": "^1.9.0",
     "scored-fuzzysearch": "^1.0.5",
     "vue": "^2.6.14"
   },
diff --git a/src/background/background.js b/src/background/background.js
index e4a87ce..438cb1e 100644
--- a/src/background/background.js
+++ b/src/background/background.js
@@ -3,7 +3,6 @@ import { Manager } from "lib-iitc-manager";
 import browser from "webextension-polyfill";
 import { IS_SCRIPTING_API, IS_USERSCRIPTS_API } from "@/userscripts/env";
 import { _ } from "@/i18n";
-import { inject_gm_api, inject_plugin } from "@/userscripts/wrapper";
 import {
   onUpdatedListener,
   onRemovedListener,
@@ -13,9 +12,14 @@ import {
 import "./requests";
 import { strToBase64 } from "@/strToBase64";
 import {
-  is_userscripts_api_available,
+  init_userscripts_api,
   is_iitc_enabled,
+  is_userscripts_api_available,
 } from "@/userscripts/utils";
+import {
+  inject_plugin_via_content_scripts,
+  manage_userscripts_api,
+} from "@/background/injector";
 
 const manager = new Manager({
   storage: browser.storage.local,
@@ -42,19 +46,17 @@ const manager = new Manager({
     } catch {
       // If popup is closed, message goes nowhere and an error occurs. Ignore.
     }
-    if (IS_USERSCRIPTS_API) {
-      is_iitc_enabled().then((status) => {
-        if (status) {
-          init_userscripts_api();
-          manager.inject().then();
-        }
-      });
-    }
   },
   inject_plugin: async (plugin) => {
-    await inject_plugin(plugin);
+    if (IS_USERSCRIPTS_API) return;
+
+    const iitc_status = await is_iitc_enabled();
+    if (iitc_status === false) return;
+
+    await inject_plugin_via_content_scripts(plugin, true);
   },
-  is_daemon: IS_USERSCRIPTS_API,
+  plugin_event: async (data) => await manage_userscripts_api(data),
+  is_daemon: true,
 });
 
 manager.run().then();
@@ -73,19 +75,19 @@ browser.runtime.onMessage.addListener(async (request) => {
       await onRequestOpenIntel();
       break;
     case "toggleIITC":
+      await onToggleIITC(request.value);
+      if (IS_USERSCRIPTS_API && request.value === true) {
+        await initUserscriptsApi();
+      }
+      break;
+    case "popupWasOpened":
       if (IS_USERSCRIPTS_API) {
-        await manage_user_scripts_status(request.value);
+        await initUserscriptsApi();
       }
-      await onToggleIITC(request.value);
       break;
     case "xmlHttpRequestHandler":
       await xmlHttpRequestHandler(request.value);
       break;
-  }
-});
-
-browser.runtime.onMessage.addListener(async function (request) {
-  switch (request.type) {
     case "managePlugin":
       await manager.managePlugin(request.uid, request.action);
       break;
@@ -239,24 +241,28 @@ async function xmlHttpRequestHandler(data) {
   }
 }
 
-const init_userscripts_api = () => {
-  if (!is_userscripts_api_available) return;
-  chrome.userScripts.configureWorld({
-    csp: "script-src 'self' 'unsafe-inline'",
-    messaging: true,
-  });
-  inject_gm_api();
-};
+async function initUserscriptsApi() {
+  if (IS_SCRIPTING_API) return;
 
-async function manage_user_scripts_status(status) {
-  if (status === true) {
-    init_userscripts_api();
-    manager.inject().then();
-  } else {
-    try {
-      await chrome.userScripts.unregister();
-    } catch (e) {
-      console.log(e);
-    }
-  }
+  let scripts = [];
+  try {
+    scripts = await chrome.userScripts.getScripts();
+    // eslint-disable-next-line no-empty
+  } catch {}
+
+  const is_gm_api_plugin_exist = scripts.some(
+    (script) => script.id === "gm_api"
+  );
+  if (is_gm_api_plugin_exist) return;
+
+  init_userscripts_api();
+  const plugins_event = {
+    event: "add",
+    plugins: await manager.getEnabledPlugins(),
+  };
+  await manage_userscripts_api(plugins_event);
 }
+
+self.addEventListener("activate", () => {
+  initUserscriptsApi().then();
+});
diff --git a/src/background/injector.js b/src/background/injector.js
index 383b4a7..bd999b2 100644
--- a/src/background/injector.js
+++ b/src/background/injector.js
@@ -33,39 +33,48 @@ export async function inject_plugin_via_content_scripts(plugin, use_gm_api) {
   }
 }
 
-export async function inject_plugin_via_userscripts_api(plugin, use_gm_api) {
+export async function manage_userscripts_api(plugins_event) {
   if (!is_userscripts_api_available) return;
 
-  if (use_gm_api) {
-    plugin.code = await gm_api_for_plugin(plugin, 0);
-  }
+  const event = plugins_event.event;
+  const plugins = plugins_event.plugins;
+  const use_gm_api = plugins_event.use_gm_api === true;
 
-  let scripts = [];
-  try {
-    scripts = await chrome.userScripts.getScripts();
-  } catch (e) {
-    console.log(e);
-    return;
+  if (event === "remove") {
+    const remove_ids = Object.keys(plugins);
+    try {
+      await browser.userScripts.unregister({ ids: remove_ids });
+    } catch (e) {
+      console.log("an error occurred while unregistering the plugin", e);
+    }
   }
-  const plugin_obj = [
-    {
+
+  let plugins_obj = [];
+  for (let plugin of Object.values(plugins)) {
+    if (use_gm_api) {
+      plugin.code = await gm_api_for_plugin(plugin, 0);
+    }
+    plugins_obj.push({
       id: plugin.uid,
       matches:
         plugin.uid === "gm_api" ? ["https://*/*"] : getPluginMatches(plugin),
       js: [{ code: plugin.code }],
       runAt: plugin.uid === "gm_api" ? "document_start" : "document_end",
       world: "MAIN",
-    },
-  ];
-
-  const is_exist = scripts.some((script) => script.id === plugin.uid);
-  if (!is_exist) {
-    await chrome.userScripts.register(plugin_obj);
-    return;
+    });
   }
 
-  const exist_script = scripts.find((script) => script.id === plugin.uid);
-  if (exist_script.js[0].code !== plugin_obj[0].js[0].code) {
-    await chrome.userScripts.update(plugin_obj);
+  if (event === "add") {
+    try {
+      await browser.userScripts.register(plugins_obj);
+    } catch (e) {
+      console.log("an error occurred while registering the plugin", e);
+    }
+  } else if (event === "update") {
+    try {
+      await browser.userScripts.update(plugins_obj);
+    } catch (e) {
+      console.log("an error occurred while updating the plugin", e);
+    }
   }
 }
diff --git a/src/background/intel.js b/src/background/intel.js
index 19bf9a6..57be1d8 100644
--- a/src/background/intel.js
+++ b/src/background/intel.js
@@ -2,6 +2,7 @@
 import browser from "webextension-polyfill";
 import { getTabsToInject } from "@/background/utils";
 import { is_iitc_enabled } from "@/userscripts/utils";
+import { IS_USERSCRIPTS_API } from "@/userscripts/env";
 
 let lastIITCTab = null;
 
@@ -24,15 +25,24 @@ export async function onRequestOpenIntel() {
   }
 }
 
-export async function onToggleIITC(value) {
-  await browser.storage.local.set({ IITC_is_enabled: value });
+export async function onToggleIITC(status) {
+  await browser.storage.local.set({ IITC_is_enabled: status });
 
-  // Fetch all completly loaded Ingress Intel tabs
-  const tabs = await getTabsToInject();
+  if (IS_USERSCRIPTS_API) {
+    if (status === false) {
+      try {
+        await browser.userScripts.unregister();
+        // eslint-disable-next-line no-empty
+      } catch {}
+    }
+  } else {
+    // Fetch all completly loaded Ingress Intel tabs
+    const tabs = await getTabsToInject();
 
-  for (let tab of Object.values(tabs)) {
-    if (isIngressIntelUrl(tab.url)) {
-      await browser.tabs.reload(tab.id);
+    for (let tab of Object.values(tabs)) {
+      if (isIngressIntelUrl(tab.url)) {
+        await browser.tabs.reload(tab.id);
+      }
     }
   }
 }
diff --git a/src/popup/App.vue b/src/popup/App.vue
index 2801abd..cf490d1 100644
--- a/src/popup/App.vue
+++ b/src/popup/App.vue
@@ -34,6 +34,7 @@ import Message from "./components/Message";
 import Alert from "./components/Alert";
 
 import * as data from "./data.js";
+import browser from "webextension-polyfill";
 
 export default {
   name: "App",
@@ -61,6 +62,7 @@ export default {
     await data.init(this);
     await data.onChangedListener(this);
     await data.onMessageListener(this);
+    await browser.runtime.sendMessage({ type: "popupWasOpened" });
   },
   methods: {
     detect_safari: function () {
diff --git a/src/userscripts/utils.js b/src/userscripts/utils.js
index ac1743b..3feeb0e 100644
--- a/src/userscripts/utils.js
+++ b/src/userscripts/utils.js
@@ -1,6 +1,7 @@
 //@license magnet:?xt=urn:btih:1f739d935676111cfff4b4693e3816e664797050&dn=gpl-3.0.txt GPL-v3
 
 import browser from "webextension-polyfill";
+import { inject_gm_api } from "@/userscripts/wrapper";
 
 export async function is_iitc_enabled() {
   const status = await browser.storage.local
@@ -12,10 +13,22 @@ export async function is_iitc_enabled() {
 export function is_userscripts_api_available() {
   try {
     // Property access which throws if developer mode is not enabled.
-    chrome.userScripts;
+    browser.userScripts;
     return true;
   } catch {
     // Not available.
     return false;
   }
 }
+
+export const init_userscripts_api = () => {
+  if (!is_userscripts_api_available) return;
+  try {
+    browser.userScripts.configureWorld({
+      csp: "script-src 'self' 'unsafe-inline'",
+      messaging: true,
+    });
+    inject_gm_api();
+    // eslint-disable-next-line no-empty
+  } catch {}
+};
diff --git a/src/userscripts/wrapper.js b/src/userscripts/wrapper.js
index 461ffa0..1767abe 100644
--- a/src/userscripts/wrapper.js
+++ b/src/userscripts/wrapper.js
@@ -2,35 +2,16 @@
 
 import browser from "webextension-polyfill";
 import { IS_USERSCRIPTS_API } from "@/userscripts/env";
-import {
-  inject_plugin_via_content_scripts,
-  inject_plugin_via_userscripts_api,
-} from "@/background/injector";
+import { manage_userscripts_api } from "@/background/injector";
 import { strToBase64 } from "@/strToBase64";
 import { getUID } from "lib-iitc-manager";
 import { inject } from "@/content-scripts/utils";
 import { GM } from "@/userscripts/gm-api";
-import { is_iitc_enabled } from "@/userscripts/utils";
 
 function getPluginHash(uid) {
   return "VMin" + strToBase64(uid);
 }
 
-export async function inject_plugin(plugin, use_gm_api) {
-  if (use_gm_api === undefined) use_gm_api = true;
-
-  const iitc_status = await is_iitc_enabled();
-  if (iitc_status === false) return;
-
-  if (IS_USERSCRIPTS_API) {
-    console.log("INJECT LIKE IS CHROME MV3");
-    await inject_plugin_via_userscripts_api(plugin, use_gm_api);
-  } else {
-    console.log("INJECT LIKE OTHER BROWSER");
-    await inject_plugin_via_content_scripts(plugin, use_gm_api);
-  }
-}
-
 export function inject_gm_api() {
   const plugin = {
     uid: "gm_api",
@@ -40,7 +21,12 @@ export function inject_gm_api() {
   };
 
   if (IS_USERSCRIPTS_API) {
-    inject_plugin_via_userscripts_api(plugin, false).then();
+    const plugins_event = {
+      event: "add",
+      use_gm_api: false,
+      plugins: [plugin],
+    };
+    manage_userscripts_api(plugins_event).then();
   } else {
     inject(plugin.code);
   }