diff --git a/manifest.json b/manifest.json
index c4ea503..c1e84d3 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,7 +1,7 @@
 {
   "name": "__MSG_name__",
   "version": "1.3.4",
-  "manifest_version": 2,
+  "manifest_version": 3,
   "description": "__MSG_desc__",
   "homepage_url": "http://thomas-roberts.co.uk",
   "icons": {
@@ -11,23 +11,16 @@
   },
   "default_locale": "en",
   "background": {
-    "scripts": [
-      "src/bg/background.js"
-    ],
-    "persistent": true
+    "service_worker": "src/bg/background.js"
   },
-  "browser_action": {
+  "action": {
     "default_icon": "icons/icon19.png",
     "default_title": "Wiktionary Search",
     "default_popup": "src/browser_action/browser_action.html"
   },
   "options_ui": {
-    "page": "src/opt/options.html",
-    "chrome_style": true
+    "page": "src/opt/options.html"
   },
-  "permissions": [
-    "contextMenus",
-    "*://*.wiktionary.org/*",
-		"storage"
-  ]
-}
\ No newline at end of file
+  "permissions": ["contextMenus", "storage"],
+  "host_permissions": ["*://*.wiktionary.org/*"]
+}
diff --git a/src/bg/background.js b/src/bg/background.js
index 81a120e..3ad6cb7 100644
--- a/src/bg/background.js
+++ b/src/bg/background.js
@@ -1,42 +1,42 @@
-// if you checked "fancy-settings" in extensionizr.com, uncomment this lines
-// var settings = new Store("settings", {
-//		 "sample_setting": "This is how you use Store.js to remember values"
-// });
-//example of using a message handler from the inject scripts
-var lang;
-chrome.storage.sync.get("language", function(obj) {
-    if (!obj.language) {
-        lang = chrome.i18n.getMessage("iso");
-    }
-});
-chrome.storage.onChanged.addListener(function(changes, namespace) {
-    chrome.storage.sync.get("language", function(obj) {
-        lang = obj.language;
-    });
-});
-
-chrome.extension.onMessage.addListener(
-    function(request, sender, sendResponse) {
-        chrome.pageAction.show(sender.tab.id);
-        sendResponse();
-    });
+// Migrate to Manifest V3 service worker
+let lang;
 
-chrome.contextMenus.create({
-    "title": chrome.i18n.getMessage("context"),
-    "contexts": ["selection"],
-    "onclick": function(e) {
+chrome.storage.sync.get('language', function (obj) {
+  if (!obj.language) {
+    lang = chrome.i18n.getMessage('iso');
+  } else {
+    lang = obj.language;
+  }
+});
 
-        var bkg = chrome.extension.getBackgroundPage();
+chrome.storage.onChanged.addListener(function (changes, namespace) {
+  chrome.storage.sync.get('language', function (obj) {
+    lang = obj.language;
+  });
+});
 
-        var url = e.pageUrl;
-        var wikURL = "http://" + lang + ".wiktionary.org/wiki/";
+chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
+  // pageAction is not available in MV3 service workers
+  // If you need to show the action, use chrome.action API from the popup or content script
+  sendResponse();
+});
 
-        if (e.selectionText) {
-            wikURL += encodeURI(e.selectionText);
-        }
-        chrome.tabs.create({
-            "url": wikURL
-        });
+chrome.runtime.onInstalled.addListener(() => {
+  chrome.contextMenus.create({
+    id: 'wiktionary-search',
+    title: chrome.i18n.getMessage('context'),
+    contexts: ['selection'],
+  });
+});
 
+chrome.contextMenus.onClicked.addListener(function (e) {
+  if (e.menuItemId === 'wiktionary-search') {
+    let wikURL = 'http://' + lang + '.wiktionary.org/wiki/';
+    if (e.selectionText) {
+      wikURL += encodeURI(e.selectionText);
     }
-});
\ No newline at end of file
+    chrome.tabs.create({
+      url: wikURL,
+    });
+  }
+});