diff --git a/packages/extension/package.json b/packages/extension/package.json
index d50c057e0cf..84708736ec3 100644
--- a/packages/extension/package.json
+++ b/packages/extension/package.json
@@ -11,6 +11,8 @@
   },
   "devDependencies": {
     "@types/chrome": "^0.0.86",
+    "@types/firefox-webext-browser": "^67.0.1",
+    "extensionizer": "^1.0.1",
     "extract-loader": "^3.1.0",
     "file-loader": "^3.0.1",
     "html-loader": "^0.5.5"
diff --git a/packages/extension/src/background/ChromeStore.ts b/packages/extension/src/background/ChromeStore.ts
index 4e344297fdb..72a38e4a0c1 100644
--- a/packages/extension/src/background/ChromeStore.ts
+++ b/packages/extension/src/background/ChromeStore.ts
@@ -1,20 +1,22 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { KeyringStore } from '@polkadot/ui-keyring/types';
 
+import extension from 'extensionizer';
+
 const lastError = (type: string): void => {
-  const error = chrome.runtime.lastError;
+  const error = extension.runtime.lastError;
 
   if (error) {
-    console.error(`ChromeStore.${type}:: chrome.runtime.lastError:`, error);
+    console.error(`ChromeStore.${type}:: runtime.lastError:`, error);
   }
 };
 
 export default class ChromeStore implements KeyringStore {
   all (cb: (key: string, value: any) => void): void {
-    chrome.storage.local.get(null, (result: { [index: string]: any }) => {
+    extension.storage.local.get(null, (result: { [index: string]: any }) => {
       lastError('all');
 
       Object.entries(result).forEach(([key, value]) =>
@@ -24,7 +26,7 @@ export default class ChromeStore implements KeyringStore {
   }
 
   get (key: string, cb: (value: any) => void): void {
-    chrome.storage.local.get([key], (result: { [index: string]: any }) => {
+    extension.storage.local.get([key], (result: { [index: string]: any }) => {
       lastError('get');
 
       cb(result[key]);
@@ -32,7 +34,7 @@ export default class ChromeStore implements KeyringStore {
   }
 
   remove (key: string, cb?: () => void): void {
-    chrome.storage.local.remove(key, () => {
+    extension.storage.local.remove(key, () => {
       lastError('remove');
 
       cb && cb();
@@ -47,7 +49,7 @@ export default class ChromeStore implements KeyringStore {
       return;
     }
 
-    chrome.storage.local.set({ [key]: value }, () => {
+    extension.storage.local.set({ [key]: value }, () => {
       lastError('set');
 
       cb && cb();
diff --git a/packages/extension/src/background/handlers/Extension.ts b/packages/extension/src/background/handlers/Extension.ts
index cc79c556509..f00b454ee6f 100644
--- a/packages/extension/src/background/handlers/Extension.ts
+++ b/packages/extension/src/background/handlers/Extension.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/background/handlers/State.ts b/packages/extension/src/background/handlers/State.ts
index 7206efbef32..934cc56e76e 100644
--- a/packages/extension/src/background/handlers/State.ts
+++ b/packages/extension/src/background/handlers/State.ts
@@ -4,6 +4,7 @@
 
 import { AuthorizeRequest, MessageAuthorize, MessageExtrinsicSign, MessageExtrinsicSign$Response, SigningRequest } from '../types';
 
+import extension from 'extensionizer';
 import { assert } from '@polkadot/util';
 
 type AuthRequest = {
@@ -115,7 +116,7 @@ export default class State {
         : (signCount ? `${signCount}` : '')
     );
 
-    chrome.browserAction.setBadgeText({ text });
+    extension.browserAction.setBadgeText({ text });
   }
 
   async authorizeUrl (url: string, request: MessageAuthorize): Promise<boolean> {
diff --git a/packages/extension/src/background/handlers/Tabs.ts b/packages/extension/src/background/handlers/Tabs.ts
index cb3c4a01e1a..b1bb167dc32 100644
--- a/packages/extension/src/background/handlers/Tabs.ts
+++ b/packages/extension/src/background/handlers/Tabs.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/background/handlers/index.ts b/packages/extension/src/background/handlers/index.ts
index 124a1934b81..6d974767d2f 100644
--- a/packages/extension/src/background/handlers/index.ts
+++ b/packages/extension/src/background/handlers/index.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/background/index.ts b/packages/extension/src/background/index.ts
index b2953dcb0f6..d6bbfbfc4c2 100644
--- a/packages/extension/src/background/index.ts
+++ b/packages/extension/src/background/index.ts
@@ -1,7 +1,9 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import extension from 'extensionizer';
+
 // Runs in the extension background, handling all keyring access
 
 import keyring from '@polkadot/ui-keyring';
@@ -10,8 +12,8 @@ import { cryptoWaitReady } from '@polkadot/util-crypto';
 import ChromeStore from './ChromeStore';
 import handlers from './handlers';
 
-chrome.browserAction.setBadgeBackgroundColor({ color: '#ff0000' });
-chrome.runtime.onMessage.addListener(handlers);
+extension.browserAction.setBadgeBackgroundColor({ color: '#ff0000' });
+extension.runtime.onMessage.addListener(handlers);
 
 cryptoWaitReady()
   .then(() => {
diff --git a/packages/extension/src/background/types.ts b/packages/extension/src/background/types.ts
index 173f7fd8b03..b2290449182 100644
--- a/packages/extension/src/background/types.ts
+++ b/packages/extension/src/background/types.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/events.ts b/packages/extension/src/events.ts
index 48b923775ab..8c54d07847d 100644
--- a/packages/extension/src/events.ts
+++ b/packages/extension/src/events.ts
@@ -1,10 +1,19 @@
-// Copyright 2019 @polkadot/extension-bg authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+// for FireFox, we need to listent here to allow origin restrictions to not
+// be an issue (otherwise we cannot read the properties on the created events)
+// const contentDocument = typeof gBrowser !== 'undefined'
+//   ? gBrowser.selectedBrowser.contentDocument
+//   : document;
+const eventTarget = document;
+
 const events = {
   request: 'PolkadotJsWebRequest',
   response: 'PolkadotJsWebResponse'
 };
 
+export { eventTarget };
+
 export default events;
diff --git a/packages/extension/src/extensionizer.d.ts b/packages/extension/src/extensionizer.d.ts
new file mode 100644
index 00000000000..df4244b2d0a
--- /dev/null
+++ b/packages/extension/src/extensionizer.d.ts
@@ -0,0 +1,15 @@
+// Copyright 2019 @polkadot/extension authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+declare var gBrowser: undefined | {
+  selectedBrowser: {
+    contentDocument: Document
+  }
+};
+
+declare module 'extensionizer' {
+  const extensionizer: typeof chrome;
+
+  export default extensionizer;
+}
diff --git a/packages/extension/src/inject/Accounts.ts b/packages/extension/src/inject/Accounts.ts
index d68b61608e4..c4c4e1bb182 100644
--- a/packages/extension/src/inject/Accounts.ts
+++ b/packages/extension/src/inject/Accounts.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-inject authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/inject/Injected.ts b/packages/extension/src/inject/Injected.ts
index b9d30d7be69..156a4d8f927 100644
--- a/packages/extension/src/inject/Injected.ts
+++ b/packages/extension/src/inject/Injected.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-inject authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/inject/Signer.ts b/packages/extension/src/inject/Signer.ts
index 792483f1173..77a416bbaae 100644
--- a/packages/extension/src/inject/Signer.ts
+++ b/packages/extension/src/inject/Signer.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-inject authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/inject/index.ts b/packages/extension/src/inject/index.ts
index 40638e8be71..679b04a7594 100644
--- a/packages/extension/src/inject/index.ts
+++ b/packages/extension/src/inject/index.ts
@@ -5,7 +5,7 @@
 import { MessageTypes } from '../background/types';
 import { WindowInjected } from './types';
 
-import events from '../events';
+import events, { eventTarget } from '../events';
 import Injected from './Injected';
 
 // when sending a message from the injector to the expension, we
@@ -40,7 +40,7 @@ function sendMessage (message: MessageTypes, request: any = null): Promise<any>
 }
 
 // setup a response listener (events created by the loader for extension responses)
-document.addEventListener(events.response, (event) => {
+eventTarget.addEventListener(events.response, (event) => {
   const response = (event as CustomEvent).detail;
   const promise = callbacks[response.id];
 
@@ -58,11 +58,14 @@ document.addEventListener(events.response, (event) => {
   }
 });
 
+// small helper with the typescript types, just cast window
+const windowInject = window as WindowInjected;
+
 // don't clobber the existing object, we will add it it (or create as needed)
-(window as WindowInjected).injectedWeb3 = (window as WindowInjected).injectedWeb3 || {};
+windowInject.injectedWeb3 = windowInject.injectedWeb3 || {};
 
 // add our enable function
-(window as WindowInjected).injectedWeb3['polkadot-js'] = {
+windowInject.injectedWeb3['polkadot-js'] = {
   name: 'polkadot-js', // process.env.PKG_NAME as string,
   version: process.env.PKG_VERSION as string,
   enable: (origin: string): Promise<Injected> =>
diff --git a/packages/extension/src/inject/types.ts b/packages/extension/src/inject/types.ts
index ad596ef20b7..6e92f60acc6 100644
--- a/packages/extension/src/inject/types.ts
+++ b/packages/extension/src/inject/types.ts
@@ -1,4 +1,4 @@
-// Copyright 2019 @polkadot/extension-inject authors & contributors
+// Copyright 2019 @polkadot/extension authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/extension/src/loader.ts b/packages/extension/src/loader.ts
index 33f136f2753..2dcdf61970c 100644
--- a/packages/extension/src/loader.ts
+++ b/packages/extension/src/loader.ts
@@ -2,19 +2,22 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import events from './events';
+import extension from 'extensionizer';
+
+import events, { eventTarget } from './events';
 
 function sendResponse (detail: any): void {
-  document.dispatchEvent(new CustomEvent(events.response, { detail }));
+  // create the custom event, this will be handled on the injection script
+  eventTarget.dispatchEvent(new CustomEvent(events.response, { detail }));
 }
 
 // Handle all custom events, passing messages to the extension
-document.addEventListener(events.request, (event) => {
+eventTarget.addEventListener(events.request, (event) => {
   // get the request as part of the the event detailt
   const request = (event as CustomEvent).detail;
 
   // pass the detail as-is as a message to the extension
-  chrome.runtime.sendMessage(request, (response) => {
+  extension.runtime.sendMessage(request, (response) => {
     if (!response) {
       // no data, send diconnected/unknown error
       sendResponse({ id: request.id, error: 'Unknown response' });
@@ -28,7 +31,7 @@ document.addEventListener(events.request, (event) => {
 // inject our data injector
 const script = document.createElement('script');
 
-script.src = chrome.extension.getURL('inject.js');
+script.src = extension.extension.getURL('inject.js');
 script.onload = (): void => {
   // remove the injecting tag when loaded
   if (script.parentNode) {
diff --git a/yarn.lock b/yarn.lock
index ff1174abc93..e2822edf705 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2121,6 +2121,11 @@
   resolved "https://registry.yarnpkg.com/@types/filewriter/-/filewriter-0.0.28.tgz#c054e8af4d9dd75db4e63abc76f885168714d4b3"
   integrity sha1-wFTor02d11205jq8dviFFocU1LM=
 
+"@types/firefox-webext-browser@^67.0.1":
+  version "67.0.1"
+  resolved "https://registry.yarnpkg.com/@types/firefox-webext-browser/-/firefox-webext-browser-67.0.1.tgz#92e3eb4440b56ab43eb93891ea4a3f33516fa7d7"
+  integrity sha512-+RE7MDu8EQ5EcQe7i0378oCvu1Sf9fEtRdPakYfdcEr79v7wTpO/meQXv9JLqvy7FwM2/9D8cwV7GyclXgRtxA==
+
 "@types/fs-extra@^5.0.3":
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/@types/fs-extra/-/fs-extra-5.1.0.tgz#2a325ef97901504a3828718c390d34b8426a10a1"
@@ -5666,6 +5671,11 @@ extend@~3.0.2:
   resolved "https://registry.yarnpkg.com/extend/-/extend-3.0.2.tgz#f8b1136b4071fbd8eb140aff858b1019ec2915fa"
   integrity sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==
 
+extensionizer@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/extensionizer/-/extensionizer-1.0.1.tgz#504544239a7610ba8404b15c1832091a37768d09"
+  integrity sha512-UES5CSOYqshNsWFrpORcQR47+ph6UvQK25mguD44IyeMemt40CG+LTZrH1PgpGUHX3w7ACtNQnmM0J+qEe8G0Q==
+
 external-editor@^3.0.3:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/external-editor/-/external-editor-3.0.3.tgz#5866db29a97826dbe4bf3afd24070ead9ea43a27"