diff --git a/frontend/src/app/shared/services/chustomization.service.spec.ts b/frontend/src/app/shared/services/chustomization.service.spec.ts
new file mode 100644
index 0000000000..d209fe0ecd
--- /dev/null
+++ b/frontend/src/app/shared/services/chustomization.service.spec.ts
@@ -0,0 +1,38 @@
+import { TestBed } from '@angular/core/testing';
+import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
+import { CustomizationService } from "./customization.service";
+import { DOCUMENT } from "@angular/common";
+import { ConfigService } from "../../config.service";
+import { Observable, of } from "rxjs";
+
+describe('CustomizationService', () => {
+  let service: CustomizationService;
+
+  const body = {
+    title: "title",
+    favicon: "favicon",
+    logo: "logo",
+    customStyles: {cssVar1: "foo"}
+  };
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      imports: [HttpClientTestingModule],
+      providers: [
+        { provide: DOCUMENT, useValue: undefined},
+        { provide: ConfigService, useValue: {
+            config$: of(body)
+          }}
+      ]
+    });
+    service = TestBed.inject(CustomizationService);
+  });
+
+  it('should be created', () => {
+    const currentConfig = service.getCurrentConfig();
+    expect(currentConfig?.title).toBe(body.title)
+    expect(currentConfig?.logo).toBe(body.logo)
+    expect(currentConfig?.favicon).toBe(body.favicon)
+    expect(currentConfig?.customStyles['cssVar1']).toBe(body.customStyles['cssVar1'])
+  });
+});
diff --git a/frontend/src/app/shared/services/customization.service.ts b/frontend/src/app/shared/services/customization.service.ts
index 75e34cdb3d..e96215cc12 100644
--- a/frontend/src/app/shared/services/customization.service.ts
+++ b/frontend/src/app/shared/services/customization.service.ts
@@ -18,6 +18,10 @@ export class CustomizationService {
     });
   }
 
+  public getCurrentConfig() {
+    return this.currentConfig;
+  }
+
   private updateCustomizations(config: CustomizationConfig) {
     this.setTitle(config.title);
     this.setFavicon(config.favicon);
@@ -31,6 +35,10 @@ export class CustomizationService {
       return;
     }
 
+    if (!this.document) {
+      return;
+    }
+
     this.document.getElementById('favicon')?.setAttribute('href', favicon);
   }
 
@@ -38,6 +46,11 @@ export class CustomizationService {
     if (!title || this.currentConfig?.title === title) {
       return;
     }
+
+    if (!this.document) {
+      return;
+    }
+
     this.document.querySelector('title')!.innerHTML = title;
   }
 
@@ -59,6 +72,10 @@ export class CustomizationService {
       return;
     }
 
+    if (!this.document) {
+      return;
+    }
+
     const styles = this.document.querySelector('html')!.style;
     if (!styles) {
       return;