diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-channel.js b/plugins/chat/assets/javascripts/discourse/components/chat-channel.js
index 255b2b6b5d3..3f7c7dcf446 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-channel.js
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-channel.js
@@ -26,7 +26,7 @@ import ChatMessagesLoader from "discourse/plugins/chat/discourse/lib/chat-messag
 import { cached, tracked } from "@glimmer/tracking";
 import discourseDebounce from "discourse-common/lib/debounce";
 import DiscourseURL from "discourse/lib/url";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import {
   FUTURE,
   PAST,
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-composer.js b/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
index d4c921e1c4c..5059ac894a0 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
@@ -6,7 +6,7 @@ import { cancel, next } from "@ember/runloop";
 import { cloneJSON } from "discourse-common/lib/object";
 import { chatComposerButtons } from "discourse/plugins/chat/discourse/lib/chat-composer-buttons";
 import TextareaInteractor from "discourse/plugins/chat/discourse/lib/textarea-interactor";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import userSearch from "discourse/lib/user-search";
 import { findRawTemplate } from "discourse-common/lib/raw-templates";
 import { emojiSearch, isSkinTonableEmoji } from "pretty-text/emoji";
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-mobile.gjs b/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-mobile.gjs
index 31baed3481f..1dbaf424ee0 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-mobile.gjs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-mobile.gjs
@@ -1,6 +1,6 @@
 import Component from "@glimmer/component";
 import ChatMessageInteractor from "discourse/plugins/chat/discourse/lib/chat-message-interactor";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import { tracked } from "@glimmer/tracking";
 import discourseLater from "discourse-common/lib/later";
 import { action } from "@ember/object";
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs b/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
index 9d10eb3486d..813413956fc 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
@@ -6,7 +6,7 @@ import { cancel, schedule } from "@ember/runloop";
 import { inject as service } from "@ember/service";
 import discourseLater from "discourse-common/lib/later";
 import isZoomed from "discourse/plugins/chat/discourse/lib/zoom-check";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import ChatMessageInteractor from "discourse/plugins/chat/discourse/lib/chat-message-interactor";
 import discourseDebounce from "discourse-common/lib/debounce";
 import { bind } from "discourse-common/utils/decorators";
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-thread.js b/plugins/chat/assets/javascripts/discourse/components/chat-thread.js
index 7908b0b526e..68cd0ed68a0 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-thread.js
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-thread.js
@@ -10,7 +10,7 @@ import { inject as service } from "@ember/service";
 import { cancel, next } from "@ember/runloop";
 import { resetIdle } from "discourse/lib/desktop-notifications";
 import ChatMessagesLoader from "discourse/plugins/chat/discourse/lib/chat-messages-loader";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import {
   FUTURE,
   PAST,
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat/selection-manager.js b/plugins/chat/assets/javascripts/discourse/components/chat/selection-manager.js
index 9614e7b6d13..089e1acd1bc 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat/selection-manager.js
+++ b/plugins/chat/assets/javascripts/discourse/components/chat/selection-manager.js
@@ -1,7 +1,7 @@
 import Component from "@glimmer/component";
 import { action } from "@ember/object";
 import { clipboardCopyAsync } from "discourse/lib/utilities";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import { isTesting } from "discourse-common/config/environment";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { inject as service } from "@ember/service";
diff --git a/plugins/chat/assets/javascripts/discourse/components/styleguide/chat-message.js b/plugins/chat/assets/javascripts/discourse/components/styleguide/chat-message.js
index 0d471a6fa2e..05ebc3031f7 100644
--- a/plugins/chat/assets/javascripts/discourse/components/styleguide/chat-message.js
+++ b/plugins/chat/assets/javascripts/discourse/components/styleguide/chat-message.js
@@ -2,7 +2,7 @@ import Component from "@glimmer/component";
 import fabricators from "discourse/plugins/chat/discourse/lib/fabricators";
 import { action } from "@ember/object";
 import ChatMessagesManager from "discourse/plugins/chat/discourse/lib/chat-messages-manager";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import { inject as service } from "@ember/service";
 
 export default class ChatStyleguideChatMessage extends Component {
diff --git a/plugins/chat/assets/javascripts/discourse/initializers/chat-setup.js b/plugins/chat/assets/javascripts/discourse/initializers/chat-setup.js
index a702751ea0a..48e4c6af77e 100644
--- a/plugins/chat/assets/javascripts/discourse/initializers/chat-setup.js
+++ b/plugins/chat/assets/javascripts/discourse/initializers/chat-setup.js
@@ -1,7 +1,7 @@
 import { withPluginApi } from "discourse/lib/plugin-api";
 import I18n from "I18n";
 import { bind } from "discourse-common/utils/decorators";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwnerWithFallback } from "discourse-common/lib/get-owner";
 import { MENTION_KEYWORDS } from "discourse/plugins/chat/discourse/components/chat-message";
 import { clearChatComposerButtons } from "discourse/plugins/chat/discourse/lib/chat-composer-buttons";
 import ChannelHashtagType from "discourse/plugins/chat/discourse/lib/hashtag-types/channel";
@@ -121,7 +121,9 @@ export default {
       // we want to decorate the chat quote dates regardless
       // of whether the current user has chat enabled
       api.decorateCookedElement((elem) => {
-        const currentUser = getOwner(this).lookup("service:current-user");
+        const currentUser = getOwnerWithFallback(this).lookup(
+          "service:current-user"
+        );
         const currentUserTimezone = currentUser?.user_option?.timezone;
         const chatTranscriptElements =
           elem.querySelectorAll(".chat-transcript");
diff --git a/plugins/chat/assets/javascripts/discourse/models/chat-channel.js b/plugins/chat/assets/javascripts/discourse/models/chat-channel.js
index 40600163531..4d3637cf65a 100644
--- a/plugins/chat/assets/javascripts/discourse/models/chat-channel.js
+++ b/plugins/chat/assets/javascripts/discourse/models/chat-channel.js
@@ -5,7 +5,7 @@ import { tracked } from "@glimmer/tracking";
 import slugifyChannel from "discourse/plugins/chat/discourse/lib/slugify-channel";
 import ChatThreadsManager from "discourse/plugins/chat/discourse/lib/chat-threads-manager";
 import ChatMessagesManager from "discourse/plugins/chat/discourse/lib/chat-messages-manager";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwnerWithFallback } from "discourse-common/lib/get-owner";
 import guid from "pretty-text/guid";
 import ChatDirectMessage from "discourse/plugins/chat/discourse/models/chat-direct-message";
 import ChatChannelArchive from "discourse/plugins/chat/discourse/models/chat-channel-archive";
@@ -70,8 +70,8 @@ export default class ChatChannel {
   @tracked tracking;
   @tracked threadingEnabled = false;
 
-  threadsManager = new ChatThreadsManager(getOwner(this));
-  messagesManager = new ChatMessagesManager(getOwner(this));
+  threadsManager = new ChatThreadsManager(getOwnerWithFallback(this));
+  messagesManager = new ChatMessagesManager(getOwnerWithFallback(this));
 
   @tracked _currentUserMembership;
   @tracked _lastMessage;
@@ -101,7 +101,7 @@ export default class ChatChannel {
       this.archive = ChatChannelArchive.create(args);
     }
 
-    this.tracking = new ChatTrackingState(getOwner(this));
+    this.tracking = new ChatTrackingState(getOwnerWithFallback(this));
     this.lastMessage = args.last_message;
     this.meta = args.meta;
   }
diff --git a/plugins/chat/assets/javascripts/discourse/models/chat-message.js b/plugins/chat/assets/javascripts/discourse/models/chat-message.js
index f9c0290e018..fa184629793 100644
--- a/plugins/chat/assets/javascripts/discourse/models/chat-message.js
+++ b/plugins/chat/assets/javascripts/discourse/models/chat-message.js
@@ -6,7 +6,7 @@ import Bookmark from "discourse/models/bookmark";
 import I18n from "I18n";
 import { generateCookFunction, parseMentions } from "discourse/lib/text";
 import transformAutolinks from "discourse/plugins/chat/discourse/lib/transform-auto-links";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwnerWithFallback } from "discourse-common/lib/get-owner";
 import discourseLater from "discourse-common/lib/later";
 
 export default class ChatMessage {
@@ -329,7 +329,7 @@ export default class ChatMessage {
   }
 
   get #markdownOptions() {
-    const site = getOwner(this).lookup("service:site");
+    const site = getOwnerWithFallback(this).lookup("service:site");
     return {
       featuresOverride:
         site.markdown_additional_options?.chat?.limited_pretty_text_features,
diff --git a/plugins/chat/assets/javascripts/discourse/models/chat-thread.js b/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
index 841f5ae2c98..94f2a7bfb99 100644
--- a/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
+++ b/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
@@ -1,4 +1,4 @@
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwnerWithFallback } from "discourse-common/lib/get-owner";
 import ChatMessagesManager from "discourse/plugins/chat/discourse/lib/chat-messages-manager";
 import { escapeExpression } from "discourse/lib/utilities";
 import { tracked } from "@glimmer/tracking";
@@ -33,7 +33,7 @@ export default class ChatThread {
   @tracked currentUserMembership = null;
   @tracked preview = null;
 
-  messagesManager = new ChatMessagesManager(getOwner(this));
+  messagesManager = new ChatMessagesManager(getOwnerWithFallback(this));
 
   constructor(channel, args = {}) {
     this.id = args.id;
@@ -55,7 +55,7 @@ export default class ChatThread {
       );
     }
 
-    this.tracking = new ChatTrackingState(getOwner(this));
+    this.tracking = new ChatTrackingState(getOwnerWithFallback(this));
     this.preview = ChatThreadPreview.create(args.preview);
   }
 
diff --git a/plugins/chat/assets/javascripts/discourse/services/chat-tracking-state-manager.js b/plugins/chat/assets/javascripts/discourse/services/chat-tracking-state-manager.js
index 208eac437b6..0f16965e2d1 100644
--- a/plugins/chat/assets/javascripts/discourse/services/chat-tracking-state-manager.js
+++ b/plugins/chat/assets/javascripts/discourse/services/chat-tracking-state-manager.js
@@ -2,7 +2,7 @@ import Service, { inject as service } from "@ember/service";
 import discourseDebounce from "discourse-common/lib/debounce";
 import { cancel } from "@ember/runloop";
 import ChatTrackingState from "discourse/plugins/chat/discourse/models/chat-tracking-state";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 
 /**
  * This service is used to provide a global interface to tracking individual
diff --git a/plugins/chat/test/javascripts/unit/lib/chat-emoji-reaction-store-test.js b/plugins/chat/test/javascripts/unit/lib/chat-emoji-reaction-store-test.js
index 2f34312a6d5..e0fe924730a 100644
--- a/plugins/chat/test/javascripts/unit/lib/chat-emoji-reaction-store-test.js
+++ b/plugins/chat/test/javascripts/unit/lib/chat-emoji-reaction-store-test.js
@@ -1,7 +1,10 @@
 import { module, test } from "qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
+import { setupTest } from "ember-qunit";
 
 module("Discourse Chat | Unit | chat-emoji-reaction-store", function (hooks) {
+  setupTest(hooks);
+
   hooks.beforeEach(function () {
     this.siteSettings = getOwner(this).lookup("service:site-settings");
     this.chatEmojiReactionStore = getOwner(this).lookup(
diff --git a/plugins/chat/test/javascripts/unit/services/chat-channel-info-route-origin-manager-test.js b/plugins/chat/test/javascripts/unit/services/chat-channel-info-route-origin-manager-test.js
index c4a37c337f6..fdc226eefe9 100644
--- a/plugins/chat/test/javascripts/unit/services/chat-channel-info-route-origin-manager-test.js
+++ b/plugins/chat/test/javascripts/unit/services/chat-channel-info-route-origin-manager-test.js
@@ -1,10 +1,13 @@
 import { module, test } from "qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import { ORIGINS } from "discourse/plugins/chat/discourse/services/chat-channel-info-route-origin-manager";
+import { setupTest } from "ember-qunit";
 
 module(
   "Discourse Chat | Unit | Service | chat-channel-info-route-origin-manager",
   function (hooks) {
+    setupTest(hooks);
+
     hooks.beforeEach(function () {
       this.manager = getOwner(this).lookup(
         "service:chat-channel-info-route-origin-manager"
diff --git a/plugins/chat/test/javascripts/unit/services/chat-drafts-manager-test.js b/plugins/chat/test/javascripts/unit/services/chat-drafts-manager-test.js
index 9c5338cddf9..9c256c9aa11 100644
--- a/plugins/chat/test/javascripts/unit/services/chat-drafts-manager-test.js
+++ b/plugins/chat/test/javascripts/unit/services/chat-drafts-manager-test.js
@@ -1,6 +1,6 @@
 import { module, test } from "qunit";
 import { setupTest } from "ember-qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import fabricators from "discourse/plugins/chat/discourse/lib/fabricators";
 
 module(
diff --git a/plugins/chat/test/javascripts/unit/services/chat-drawer-size-test.js b/plugins/chat/test/javascripts/unit/services/chat-drawer-size-test.js
index 3bc9ca81adb..00272d4efad 100644
--- a/plugins/chat/test/javascripts/unit/services/chat-drawer-size-test.js
+++ b/plugins/chat/test/javascripts/unit/services/chat-drawer-size-test.js
@@ -1,7 +1,10 @@
 import { module, test } from "qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
+import { setupTest } from "ember-qunit";
 
 module("Discourse Chat | Unit | Service | chat-drawer-size", function (hooks) {
+  setupTest(hooks);
+
   hooks.beforeEach(function () {
     this.subject = getOwner(this).lookup("service:chat-drawer-size");
   });
diff --git a/plugins/chat/test/javascripts/unit/services/chat-emoji-picker-manager-test.js b/plugins/chat/test/javascripts/unit/services/chat-emoji-picker-manager-test.js
index 1276368faa9..ea57f78783d 100644
--- a/plugins/chat/test/javascripts/unit/services/chat-emoji-picker-manager-test.js
+++ b/plugins/chat/test/javascripts/unit/services/chat-emoji-picker-manager-test.js
@@ -1,7 +1,8 @@
 import { module, test } from "qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import pretender from "discourse/tests/helpers/create-pretender";
 import { settled } from "@ember/test-helpers";
+import { setupTest } from "ember-qunit";
 
 function emojisReponse() {
   return { favorites: [{ name: "sad" }] };
@@ -10,6 +11,8 @@ function emojisReponse() {
 module(
   "Discourse Chat | Unit | Service | chat-emoji-picker-manager",
   function (hooks) {
+    setupTest(hooks);
+
     hooks.beforeEach(function () {
       pretender.get("/chat/emojis.json", () => {
         return [200, {}, emojisReponse()];
diff --git a/plugins/chat/test/javascripts/unit/services/chat-state-manager-test.js b/plugins/chat/test/javascripts/unit/services/chat-state-manager-test.js
index 1242caea51a..daf1e595eaf 100644
--- a/plugins/chat/test/javascripts/unit/services/chat-state-manager-test.js
+++ b/plugins/chat/test/javascripts/unit/services/chat-state-manager-test.js
@@ -2,7 +2,7 @@ import { module, test } from "qunit";
 import { setupTest } from "ember-qunit";
 import Site from "discourse/models/site";
 import sinon from "sinon";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import {
   addChatDrawerStateCallback,
   resetChatDrawerStateCallbacks,
diff --git a/plugins/chat/test/javascripts/unit/utility/plugin-api-test.js b/plugins/chat/test/javascripts/unit/utility/plugin-api-test.js
index 986fd8f7e99..86c2309ac50 100644
--- a/plugins/chat/test/javascripts/unit/utility/plugin-api-test.js
+++ b/plugins/chat/test/javascripts/unit/utility/plugin-api-test.js
@@ -1,6 +1,6 @@
 import { setupTest } from "ember-qunit";
 import { module, test } from "qunit";
-import { getOwner } from "discourse-common/lib/get-owner";
+import { getOwner } from "@ember/application";
 import { withPluginApi } from "discourse/lib/plugin-api";
 import User from "discourse/models/user";
 import ChatMessageInteractor, {