diff --git a/alfa-client/apps/admin/src/app/app.component.html b/alfa-client/apps/admin/src/app/app.component.html
index b8a2a57f0984c15be178bbfe6c5a1be5dbcbd12a..85289011b499a7322356001df49396a1a48ded32 100644
--- a/alfa-client/apps/admin/src/app/app.component.html
+++ b/alfa-client/apps/admin/src/app/app.component.html
@@ -15,7 +15,7 @@
   </header>
   <div class="flex h-screen w-full justify-center overflow-y-auto">
     <ods-navbar data-test-id="navigation">
-      <ng-container *ngIf="apiRoot | hasLink: ApiRootLinkRel.CONFIGURATION">
+      <ng-container *ngIf="apiRoot | hasLink: apiRootLinkRel.CONFIGURATION">
         <ng-container *ngIf="environment.features.benutzerRollen">
           <ods-nav-item data-test-id="users-roles-navigation" caption="Benutzer & Rollen" path="/benutzer_und_rollen">
             <ods-users-icon class="stroke-text" icon />
@@ -27,7 +27,7 @@
             <ods-mailbox-icon icon />
           </ods-nav-item>
         </ng-container>
-        <ng-container *ngIf="apiRoot | hasLink: ApiRootLinkRel.ORGANISATIONS_EINHEIT">
+        <ng-container *ngIf="apiRoot | hasLink: apiRootLinkRel.ORGANISATIONS_EINHEIT">
           <ods-nav-item
             data-test-id="organisations-einheiten-navigation"
             caption="Organisationseinheiten"
@@ -40,7 +40,7 @@
     </ods-navbar>
     <main class="flex-1 overflow-y-auto bg-white px-6 py-4">
       <router-outlet
-        *ngIf="apiRoot | hasLink: ApiRootLinkRel.CONFIGURATION; else configurationResourceLinkNotAvailable"
+        *ngIf="apiRoot | hasLink: apiRootLinkRel.CONFIGURATION; else configurationResourceLinkNotAvailable"
         data-test-id="router-outlet"
       ></router-outlet>
       <ng-template #configurationResourceLinkNotAvailable>
diff --git a/alfa-client/apps/admin/src/app/app.component.ts b/alfa-client/apps/admin/src/app/app.component.ts
index 369adaaa96d47e015faa12af07479663ec19826b..061f41f6114b92fe44fe6d2576ce286f7fbd02a2 100644
--- a/alfa-client/apps/admin/src/app/app.component.ts
+++ b/alfa-client/apps/admin/src/app/app.component.ts
@@ -15,7 +15,9 @@ export class AppComponent implements OnInit {
   readonly title = 'admin';
 
   public apiRootStateResource$: Observable<StateResource<ApiRootResource>>;
-  public environment: Environment = getEnvironmentFactory();
+  public readonly environment: Environment = getEnvironmentFactory();
+
+  public readonly apiRootLinkRel = ApiRootLinkRel;
 
   constructor(
     public authenticationService: AuthenticationService,
@@ -42,6 +44,4 @@ export class AppComponent implements OnInit {
     const { iss, state, session_state, code, ...queryParams } = this.route.snapshot.queryParams;
     return queryParams;
   }
-
-  protected readonly ApiRootLinkRel = ApiRootLinkRel;
 }
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.html b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.html
index d4298fb96d7c2a38fd1014068f02b887c438194b..3b51a8348e6f498aebb2662b7906b149375eb25b 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.html
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.html
@@ -1,5 +1,5 @@
 <ng-container *ngIf="(apiRootStateResource$ | async)?.resource as apiRoot">
-  @if (apiRoot | hasLink: ApiRootLinkRel.ORGANISATIONS_EINHEIT) {
+  @if (apiRoot | hasLink: apiRootLinkRel.ORGANISATIONS_EINHEIT) {
     <admin-organisationseinheit-form-container data-test-id="organisations-einheit-form" />
   }
 </ng-container>
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.spec.ts b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.spec.ts
index eb70d9123241996827a8440b6205cb4b25d35d8a..24743e785502b9aceeec929680b249f186befd9d 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.spec.ts
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.spec.ts
@@ -15,13 +15,11 @@ describe('OrganisationsEinheitFormPageComponent', () => {
 
   const organisationsEinheitFormSelector: string = getDataTestIdOf('organisations-einheit-form');
 
-  const apiRootStateResource$ = of(createStateResource(createApiRootResource()));
-  const apiRootService: Mock<ApiRootService> = {
-    ...mock(ApiRootService),
-    getApiRoot: jest.fn().mockReturnValue(apiRootStateResource$),
-  };
+  let apiRootService: Mock<ApiRootService>;
 
   beforeEach(async () => {
+    apiRootService = mock(ApiRootService);
+
     await TestBed.configureTestingModule({
       imports: [TechSharedModule],
       declarations: [OrganisationsEinheitFormPageComponent, MockComponent(OrganisationsEinheitFormContainerComponent)],
@@ -42,7 +40,19 @@ describe('OrganisationsEinheitFormPageComponent', () => {
 
   describe('component', () => {
     describe('ngOnInit', () => {
-      it('should get apiRoot', () => {
+      const apiRootStateResource$ = of(createStateResource(createApiRootResource()));
+
+      beforeEach(() => {
+        apiRootService.getApiRoot.mockReturnValue(apiRootStateResource$);
+      });
+
+      it('should call apiRootService getApiRoot', () => {
+        component.ngOnInit();
+
+        expect(apiRootService.getApiRoot).toHaveBeenCalled();
+      });
+
+      it('should get apiRootStateResource$', () => {
         component.ngOnInit();
 
         expect(component.apiRootStateResource$).toBe(apiRootStateResource$);
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.ts b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.ts
index 6a14ce6da44f0d1c4adf5c1e59c67dd12f163a15..3f3d7caaee6c195cafc37e47ceda66d08d4ffa25 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.ts
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-form-page/organisationseinheit-form-page.component.ts
@@ -12,9 +12,9 @@ export class OrganisationsEinheitFormPageComponent implements OnInit {
 
   public apiRootStateResource$: Observable<StateResource<ApiRootResource>> = of(createEmptyStateResource<ApiRootResource>());
 
+  public readonly apiRootLinkRel = ApiRootLinkRel;
+
   ngOnInit(): void {
     this.apiRootStateResource$ = this.apiRootService.getApiRoot();
   }
-
-  protected readonly ApiRootLinkRel = ApiRootLinkRel;
 }
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.html b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.html
index 883e3bad789094c3cb8cbebfb5be4931871a1600..81ac9db2471f4449e27b967acea804629dd0c5f1 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.html
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.html
@@ -1,5 +1,5 @@
 <ng-container *ngIf="(apiRootStateResource$ | async)?.resource as apiRoot">
-  @if (apiRoot | hasLink: ApiRootLinkRel.ORGANISATIONS_EINHEIT) {
+  @if (apiRoot | hasLink: apiRootLinkRel.ORGANISATIONS_EINHEIT) {
     <admin-organisationseinheit-container data-test-id="organisations-einheit-container" />
   }
 </ng-container>
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.spec.ts b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.spec.ts
index 17a5736eae9427dd9e1b620ef21807111e59deec..c1161e03b9678b33387383edc9cad99a5b9760be 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.spec.ts
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.spec.ts
@@ -15,13 +15,11 @@ describe('OrganisationsEinheitPageComponent', () => {
 
   const organisationsEinheitContainerSelector: string = getDataTestIdOf('organisations-einheit-container');
 
-  const apiRootStateResource$ = of(createStateResource(createApiRootResource()));
-  const apiRootService: Mock<ApiRootService> = {
-    ...mock(ApiRootService),
-    getApiRoot: jest.fn().mockReturnValue(apiRootStateResource$),
-  };
+  let apiRootService: Mock<ApiRootService>;
 
   beforeEach(async () => {
+    apiRootService = mock(ApiRootService);
+
     await TestBed.configureTestingModule({
       imports: [TechSharedModule],
       declarations: [OrganisationsEinheitPageComponent, MockComponent(OrganisationsEinheitContainerComponent)],
@@ -40,6 +38,28 @@ describe('OrganisationsEinheitPageComponent', () => {
     expect(component).toBeTruthy();
   });
 
+  describe('component', () => {
+    describe('ngOnInit', () => {
+      const apiRootStateResource$ = of(createStateResource(createApiRootResource()));
+
+      beforeEach(() => {
+        apiRootService.getApiRoot.mockReturnValue(apiRootStateResource$);
+      });
+
+      it('should call apiRootService getApiRoot', () => {
+        component.ngOnInit();
+
+        expect(apiRootService.getApiRoot).toHaveBeenCalled();
+      });
+
+      it('should get apiRootStateResource$', () => {
+        component.ngOnInit();
+
+        expect(component.apiRootStateResource$).toBe(apiRootStateResource$);
+      });
+    });
+  });
+
   describe('template', () => {
     describe('admin-organisationseinheit-container', () => {
       it('should be rendered if apiRootState has link', () => {
diff --git a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.ts b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.ts
index 08fdbd714dc2f421a2b2614f18b47d743c494011..f7f2d451c2a7a88db7dd3d7e83ce00e420768fcc 100644
--- a/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.ts
+++ b/alfa-client/apps/admin/src/pages/organisationseinheit/organisationseinheit-page/organisationseinheit-page.component.ts
@@ -1,19 +1,20 @@
 import { ApiRootLinkRel, ApiRootResource, ApiRootService } from '@alfa-client/api-root-shared';
 import { createEmptyStateResource, StateResource } from '@alfa-client/tech-shared';
-import { Component, inject } from '@angular/core';
+import { Component, inject, OnInit } from '@angular/core';
 import { Observable, of } from 'rxjs';
 
 @Component({
   selector: 'organisationseinheit-page',
   templateUrl: './organisationseinheit-page.component.html',
 })
-export class OrganisationsEinheitPageComponent {
+export class OrganisationsEinheitPageComponent implements OnInit {
   private apiRootService = inject(ApiRootService);
 
   public apiRootStateResource$: Observable<StateResource<ApiRootResource>> = of(createEmptyStateResource<ApiRootResource>());
 
+  public readonly apiRootLinkRel = ApiRootLinkRel;
+
   ngOnInit(): void {
     this.apiRootStateResource$ = this.apiRootService.getApiRoot();
   }
-  protected readonly ApiRootLinkRel = ApiRootLinkRel;
 }
diff --git a/alfa-client/apps/admin/src/pages/postfach/postfach-page/postfach-page.component.ts b/alfa-client/apps/admin/src/pages/postfach/postfach-page/postfach-page.component.ts
index e517dd361f662c17b3c69994a76f1ee131f8bcd8..362987cbbc4ed3023050483e4b4c5632eccb3c7a 100644
--- a/alfa-client/apps/admin/src/pages/postfach/postfach-page/postfach-page.component.ts
+++ b/alfa-client/apps/admin/src/pages/postfach/postfach-page/postfach-page.component.ts
@@ -6,5 +6,5 @@ import { Component } from '@angular/core';
   templateUrl: './postfach-page.component.html',
 })
 export class PostfachPageComponent {
-  public environment: Environment = getEnvironmentFactory();
+  public readonly environment: Environment = getEnvironmentFactory();
 }
diff --git a/alfa-client/apps/admin/src/pages/users-roles/user-add-page/user-add-page.component.ts b/alfa-client/apps/admin/src/pages/users-roles/user-add-page/user-add-page.component.ts
index e52105d82b847654bbd74d769a047a1bd0d48de7..4459cb7624103db427f092f92cfb59585ec3a97a 100644
--- a/alfa-client/apps/admin/src/pages/users-roles/user-add-page/user-add-page.component.ts
+++ b/alfa-client/apps/admin/src/pages/users-roles/user-add-page/user-add-page.component.ts
@@ -6,5 +6,5 @@ import { Component } from '@angular/core';
   templateUrl: './user-add-page.component.html',
 })
 export class UserAddPageComponent {
-  public environment: Environment = getEnvironmentFactory();
+  public readonly environment: Environment = getEnvironmentFactory();
 }
diff --git a/alfa-client/apps/admin/src/pages/users-roles/user-roles-page/user-roles-page.component.ts b/alfa-client/apps/admin/src/pages/users-roles/user-roles-page/user-roles-page.component.ts
index eacc7b424e712af3c12e5a182c0c9e339fa1d76b..5688b709c2a2782ad62ea98516b0fd95ae129eb1 100644
--- a/alfa-client/apps/admin/src/pages/users-roles/user-roles-page/user-roles-page.component.ts
+++ b/alfa-client/apps/admin/src/pages/users-roles/user-roles-page/user-roles-page.component.ts
@@ -6,5 +6,5 @@ import { Component } from '@angular/core';
   templateUrl: './user-roles-page.component.html',
 })
 export class UserRolesPageComponent {
-  public environment: Environment = getEnvironmentFactory();
+  public readonly environment: Environment = getEnvironmentFactory();
 }