diff --git a/web/app.js b/web/app.js
index d55ce59c9be9c..45dc9fd7e221b 100644
--- a/web/app.js
+++ b/web/app.js
@@ -57,7 +57,7 @@ import {
   version,
 } from "pdfjs-lib";
 import { AppOptions, OptionKind } from "./app_options.js";
-import { AutomationEventBus, EventBus } from "./event_utils.js";
+import { EventBus, FirefoxEventBus } from "./event_utils.js";
 import { ExternalServices, initCom, MLManager } from "web-external_services";
 import { LinkTarget, PDFLinkService } from "./pdf_link_service.js";
 import { AltTextManager } from "web-alt_text_manager";
@@ -156,6 +156,7 @@ const PDFViewerApplication = {
   isViewerEmbedded: window.parent !== window,
   url: "",
   baseUrl: "",
+  _allowedGlobalEventsPromise: null,
   _downloadUrl: "",
   _eventBusAbortController: null,
   _windowAbortController: null,
@@ -186,6 +187,10 @@ const PDFViewerApplication = {
     // initialize the `L10n`-instance as soon as possible.
     if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("GENERIC")) {
       l10nPromise = this.externalServices.createL10n();
+      if (PDFJSDev.test("MOZCENTRAL")) {
+        this._allowedGlobalEventsPromise =
+          this.externalServices.getGlobalEventNames();
+      }
     }
     this.appConfig = appConfig;
 
@@ -386,10 +391,17 @@ const PDFViewerApplication = {
    */
   async _initializeViewerComponents() {
     const { appConfig, externalServices, l10n } = this;
-
-    const eventBus = AppOptions.get("isInAutomation")
-      ? new AutomationEventBus()
-      : new EventBus();
+    let eventBus;
+    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
+      eventBus = new FirefoxEventBus(
+        await this._allowedGlobalEventsPromise,
+        externalServices,
+        AppOptions.get("isInAutomation")
+      );
+      this._allowedGlobalEventsPromise = null;
+    } else {
+      eventBus = new EventBus();
+    }
     this.eventBus = eventBus;
 
     this.overlayManager = new OverlayManager();
diff --git a/web/event_utils.js b/web/event_utils.js
index 29c30166e9f3c..dfca497d53db9 100644
--- a/web/event_utils.js
+++ b/web/event_utils.js
@@ -170,35 +170,57 @@ class EventBus {
 }
 
 /**
- * NOTE: Only used to support various PDF viewer tests in `mozilla-central`.
+ * NOTE: Only used in the Firefox build-in pdf viewer.
  */
-class AutomationEventBus extends EventBus {
+class FirefoxEventBus extends EventBus {
+  #externalServices;
+
+  #globalEventNames;
+
+  #isInAutomation;
+
+  constructor(globalEventNames, externalServices, isInAutomation) {
+    super();
+    this.#globalEventNames = globalEventNames;
+    this.#externalServices = externalServices;
+    this.#isInAutomation = isInAutomation;
+  }
+
   dispatch(eventName, data) {
     if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("MOZCENTRAL")) {
-      throw new Error("Not implemented: AutomationEventBus.dispatch");
+      throw new Error("Not implemented: FirefoxEventBus.dispatch");
     }
     super.dispatch(eventName, data);
 
-    const detail = Object.create(null);
-    if (data) {
-      for (const key in data) {
-        const value = data[key];
-        if (key === "source") {
-          if (value === window || value === document) {
-            return; // No need to re-dispatch (already) global events.
+    if (this.#isInAutomation) {
+      const detail = Object.create(null);
+      if (data) {
+        for (const key in data) {
+          const value = data[key];
+          if (key === "source") {
+            if (value === window || value === document) {
+              return; // No need to re-dispatch (already) global events.
+            }
+            continue; // Ignore the `source` property.
           }
-          continue; // Ignore the `source` property.
+          detail[key] = value;
         }
-        detail[key] = value;
       }
+      const event = new CustomEvent(eventName, {
+        bubbles: true,
+        cancelable: true,
+        detail,
+      });
+      document.dispatchEvent(event);
+    }
+
+    if (this.#globalEventNames?.has(eventName)) {
+      this.#externalServices.dispatchGlobalEvent({
+        eventName,
+        detail: data,
+      });
     }
-    const event = new CustomEvent(eventName, {
-      bubbles: true,
-      cancelable: true,
-      detail,
-    });
-    document.dispatchEvent(event);
   }
 }
 
-export { AutomationEventBus, EventBus, waitOnEventOrTimeout, WaitOnType };
+export { EventBus, FirefoxEventBus, waitOnEventOrTimeout, WaitOnType };
diff --git a/web/external_services.js b/web/external_services.js
index fa1f086b484f1..8a3043833039e 100644
--- a/web/external_services.js
+++ b/web/external_services.js
@@ -46,6 +46,12 @@ class BaseExternalServices {
   }
 
   async getNimbusExperimentData() {}
+
+  async getGlobalEventNames() {
+    return null;
+  }
+
+  dispatchGlobalEvent(_event) {}
 }
 
 export { BaseExternalServices };
diff --git a/web/firefoxcom.js b/web/firefoxcom.js
index babd142ee0eea..e431f4a081853 100644
--- a/web/firefoxcom.js
+++ b/web/firefoxcom.js
@@ -407,6 +407,14 @@ class ExternalServices extends BaseExternalServices {
     );
     return nimbusData && JSON.parse(nimbusData);
   }
+
+  async getGlobalEventNames() {
+    return FirefoxCom.requestAsync("getGlobalEventNames", null);
+  }
+
+  dispatchGlobalEvent(event) {
+    FirefoxCom.request("dispatchGlobalEvent", event);
+  }
 }
 
 export { DownloadManager, ExternalServices, initCom, MLManager, Preferences };