diff --git a/packages/firestore/CHANGELOG.md b/packages/firestore/CHANGELOG.md
index 2cac668f4b1..30390790265 100644
--- a/packages/firestore/CHANGELOG.md
+++ b/packages/firestore/CHANGELOG.md
@@ -1,4 +1,8 @@
 # Unreleased
+- [fixed] Fixed an issue where auth credentials were not respected in some
+  Firefox or Chrome extensions. (#1491)
+
+# 1.9.2
 - [fixed] Fixed an issue where auth credentials were not respected in certain
   browser environments (Electron 7, IE11 in trusted zone, UWP apps). (#1491)
 
diff --git a/packages/firestore/src/platform_browser/webchannel_connection.ts b/packages/firestore/src/platform_browser/webchannel_connection.ts
index c1b64b61e84..48674cc0e84 100644
--- a/packages/firestore/src/platform_browser/webchannel_connection.ts
+++ b/packages/firestore/src/platform_browser/webchannel_connection.ts
@@ -25,7 +25,13 @@ import {
   XhrIo
 } from '@firebase/webchannel-wrapper';
 
-import { isElectron, isIE, isReactNative, isUWP } from '@firebase/util';
+import {
+  isBrowserExtension,
+  isElectron,
+  isIE,
+  isReactNative,
+  isUWP
+} from '@firebase/util';
 
 import { Token } from '../api/credentials';
 import { DatabaseId, DatabaseInfo } from '../core/database_info';
@@ -268,7 +274,13 @@ export class WebChannelConnection implements Connection {
     // doesn't have an Origin header. So we have to exclude a few browser environments that are
     // known to (sometimes) not include an Origin. See
     // https://github.com/firebase/firebase-js-sdk/issues/1491.
-    if (!isReactNative() && !isElectron() && !isIE() && !isUWP()) {
+    if (
+      !isReactNative() &&
+      !isElectron() &&
+      !isIE() &&
+      !isUWP() &&
+      !isBrowserExtension()
+    ) {
       request.httpHeadersOverwriteParam = '$httpHeaders';
     }
 
diff --git a/packages/util/src/environment.ts b/packages/util/src/environment.ts
index cb4bd4c9b91..b7509826f16 100644
--- a/packages/util/src/environment.ts
+++ b/packages/util/src/environment.ts
@@ -72,6 +72,24 @@ export function isBrowser(): boolean {
   return typeof self === 'object' && self.self === self;
 }
 
+/**
+ * Detect browser extensions (Chrome and Firefox at least).
+ */
+interface BrowserRuntime {
+  id?: unknown;
+}
+declare const chrome: { runtime?: BrowserRuntime };
+declare const browser: { runtime?: BrowserRuntime };
+export function isBrowserExtension(): boolean {
+  const runtime =
+    typeof chrome === 'object'
+      ? chrome.runtime
+      : typeof browser === 'object'
+      ? browser.runtime
+      : undefined;
+  return typeof runtime === 'object' && runtime.id !== undefined;
+}
+
 /**
  * Detect React Native.
  *