diff --git a/addons/mail/static/src/core/common/messaging_service.js b/addons/mail/static/src/core/common/messaging_service.js
index 59df8bc1c28..16e37cfc95e 100644
--- a/addons/mail/static/src/core/common/messaging_service.js
+++ b/addons/mail/static/src/core/common/messaging_service.js
@@ -130,14 +130,6 @@ export class Messaging {
     handleNotification(notifications) {
         for (const notif of notifications) {
             switch (notif.type) {
-                case "mail.activity/updated":
-                    if (notif.payload.activity_created) {
-                        this.store.activityCounter++;
-                    }
-                    if (notif.payload.activity_deleted) {
-                        this.store.activityCounter--;
-                    }
-                    break;
                 case "mail.record/insert":
                     this._handleNotificationRecordInsert(notif);
                     break;
diff --git a/addons/mail/static/src/core/web/mail_core_web_service.js b/addons/mail/static/src/core/web/mail_core_web_service.js
index 4696d5f8fb3..2f377315ef2 100644
--- a/addons/mail/static/src/core/web/mail_core_web_service.js
+++ b/addons/mail/static/src/core/web/mail_core_web_service.js
@@ -7,6 +7,7 @@ import { registry } from "@web/core/registry";
 export class MailCoreWeb {
     constructor(env, services) {
         Object.assign(this, {
+            busService: services.bus_service,
             rpc: services.rpc,
         });
         /** @type {import("@mail/core/common/message_service").MessageService} */
@@ -34,12 +35,20 @@ export class MailCoreWeb {
                     (n1, n2) => n2.lastMessage.id - n1.lastMessage.id
                 );
             });
+            this.busService.subscribe("mail.activity/updated", (payload) => {
+                if (payload.activity_created) {
+                    this.store.activityCounter++;
+                }
+                if (payload.activity_deleted) {
+                    this.store.activityCounter--;
+                }
+            });
         });
     }
 }
 
 export const mailCoreWeb = {
-    dependencies: ["mail.message", "mail.messaging", "mail.store", "rpc"],
+    dependencies: ["bus_service", "mail.message", "mail.messaging", "mail.store", "rpc"],
     start(env, services) {
         const mailCoreWeb = reactive(new MailCoreWeb(env, services));
         mailCoreWeb.setup();