diff --git a/src/Umbraco.Web.UI.Client/index.ts b/src/Umbraco.Web.UI.Client/index.ts
index 501e5fd53a..30e91a9555 100644
--- a/src/Umbraco.Web.UI.Client/index.ts
+++ b/src/Umbraco.Web.UI.Client/index.ts
@@ -18,4 +18,21 @@ if (import.meta.env.DEV) {
 
 appElement.bypassAuth = isMocking;
 
+const CORE_PACKAGES = [
+	import('./src/packages/core/umbraco-package'),
+	import('./src/packages/settings/umbraco-package'),
+	import('./src/packages/documents/umbraco-package'),
+	import('./src/packages/media/umbraco-package'),
+	import('./src/packages/members/umbraco-package'),
+	import('./src/packages/translation/umbraco-package'),
+	import('./src/packages/users/umbraco-package'),
+	import('./src/packages/packages/umbraco-package'),
+	import('./src/packages/search/umbraco-package'),
+	import('./src/packages/templating/umbraco-package'),
+	import('./src/packages/umbraco-news/umbraco-package'),
+	import('./src/packages/tags/umbraco-package'),
+];
+
+appElement.localPackages = CORE_PACKAGES;
+
 document.body.appendChild(appElement);
diff --git a/src/Umbraco.Web.UI.Client/src/apps/app/app.element.ts b/src/Umbraco.Web.UI.Client/src/apps/app/app.element.ts
index 90bd34445f..b35f705ecd 100644
--- a/src/Umbraco.Web.UI.Client/src/apps/app/app.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/apps/app/app.element.ts
@@ -5,10 +5,10 @@ import { UUIIconRegistryEssential } from '@umbraco-ui/uui';
 import { css, html } from 'lit';
 import { customElement, property } from 'lit/decorators.js';
 
-import { UmbIconRegistry } from '@umbraco-cms/backoffice/icon';
 import type { UmbAppErrorElement } from './app-error.element';
 import { UmbAuthFlow } from './auth';
 import { UMB_APP, UmbAppContext } from './app.context';
+import { UmbIconRegistry } from '@umbraco-cms/backoffice/icon';
 import type { Guard, UmbRoute } from '@umbraco-cms/backoffice/router';
 import { pathWithoutBasePath } from '@umbraco-cms/backoffice/router';
 import { UmbLitElement } from '@umbraco-cms/internal/lit-element';
@@ -44,6 +44,9 @@ export class UmbAppElement extends UmbLitElement {
 	@property({ type: Boolean })
 	bypassAuth = false;
 
+	@property()
+	localPackages: Array<Promise<any>> = [];
+
 	private _routes: UmbRoute[] = [
 		{
 			path: 'install',
@@ -57,6 +60,9 @@ export class UmbAppElement extends UmbLitElement {
 		{
 			path: '**',
 			component: () => import('../backoffice/backoffice.element'),
+			setup: (component) => {
+				(component as any).localPackages = this.localPackages;
+			},
 			guards: [this.#isAuthorizedGuard()],
 		},
 	];
diff --git a/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.element.ts b/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.element.ts
index 803b6e1153..a400f5af37 100644
--- a/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.element.ts
@@ -1,6 +1,5 @@
-import { defineElement } from '@umbraco-ui/uui-base/lib/registration';
-import { UUITextStyles } from '@umbraco-ui/uui-css/lib';
 import { css, html } from 'lit';
+import { customElement, property } from 'lit/decorators.js';
 import { UmbExtensionInitializer } from './extension.controller';
 import { UmbBackofficeContext, UMB_BACKOFFICE_CONTEXT_TOKEN } from './backoffice.context';
 import { UmbEntryPointExtensionInitializer } from '@umbraco-cms/backoffice/extension-api';
@@ -9,28 +8,20 @@ import { UmbLitElement } from '@umbraco-cms/internal/lit-element';
 
 import './components';
 
-const CORE_PACKAGES = [
-	import('../../packages/core/umbraco-package'),
-	import('../../packages/settings/umbraco-package'),
-	import('../../packages/documents/umbraco-package'),
-	import('../../packages/media/umbraco-package'),
-	import('../../packages/members/umbraco-package'),
-	import('../../packages/translation/umbraco-package'),
-	import('../../packages/users/umbraco-package'),
-	import('../../packages/packages/umbraco-package'),
-	import('../../packages/search/umbraco-package'),
-	import('../../packages/templating/umbraco-package'),
-	import('../../packages/umbraco-news/umbraco-package'),
-	import('../../packages/tags/umbraco-package'),
-];
-
-@defineElement('umb-backoffice')
+@customElement('umb-backoffice')
 export class UmbBackofficeElement extends UmbLitElement {
+	@property()
+	set localPackages(value: Array<Promise<any>>) {
+		this.#extensionInitializer.setLocalPackages(value);
+	}
+
+	#extensionInitializer = new UmbExtensionInitializer(this, umbExtensionsRegistry);
+
 	constructor() {
 		super();
 		this.provideContext(UMB_BACKOFFICE_CONTEXT_TOKEN, new UmbBackofficeContext());
 		new UmbEntryPointExtensionInitializer(this, umbExtensionsRegistry);
-		new UmbExtensionInitializer(this, umbExtensionsRegistry, CORE_PACKAGES);
+		new UmbExtensionInitializer(this, umbExtensionsRegistry);
 	}
 
 	render() {
@@ -42,7 +33,6 @@ export class UmbBackofficeElement extends UmbLitElement {
 	}
 
 	static styles = [
-		UUITextStyles,
 		css`
 			:host {
 				display: flex;
diff --git a/src/Umbraco.Web.UI.Client/src/apps/backoffice/extension.controller.ts b/src/Umbraco.Web.UI.Client/src/apps/backoffice/extension.controller.ts
index 21fd32cb3c..147d428101 100644
--- a/src/Umbraco.Web.UI.Client/src/apps/backoffice/extension.controller.ts
+++ b/src/Umbraco.Web.UI.Client/src/apps/backoffice/extension.controller.ts
@@ -9,22 +9,21 @@ export class UmbExtensionInitializer extends UmbController {
 	host: UmbControllerHostElement;
 	#extensionRegistry: UmbBackofficeExtensionRegistry;
 	#unobserve = new Subject<void>();
-	#localPackages: Array<Promise<any>>;
+	#localPackages: Array<Promise<any>> = [];
 	#apiBaseUrl = OpenAPI.BASE;
 
-	constructor(
-		host: UmbControllerHostElement,
-		extensionRegistry: UmbBackofficeExtensionRegistry,
-		localPackages: Array<Promise<any>>
-	) {
+	constructor(host: UmbControllerHostElement, extensionRegistry: UmbBackofficeExtensionRegistry) {
 		super(host, UmbExtensionInitializer.name);
 		this.host = host;
 		this.#extensionRegistry = extensionRegistry;
+	}
+
+	setLocalPackages(localPackages: Array<Promise<any>>) {
 		this.#localPackages = localPackages;
+		this.#loadLocalPackages();
 	}
 
 	hostConnected(): void {
-		this.#loadLocalPackages();
 		this.#loadServerPackages();
 	}