diff --git a/src/config/app.config.ts b/src/config/app.config.ts
index c1af96dce..52e593032 100644
--- a/src/config/app.config.ts
+++ b/src/config/app.config.ts
@@ -20,7 +20,10 @@ export interface AppConfig {
 
 const schema = Joi.object({
   domain: Joi.string().label('HD_DOMAIN'),
-  rendererOrigin: Joi.string().optional().label('HD_RENDERER_ORIGIN'),
+  rendererOrigin: Joi.string()
+    .default(Joi.ref('domain'))
+    .optional()
+    .label('HD_RENDERER_ORIGIN'),
   port: Joi.number().default(3000).optional().label('PORT'),
   loglevel: Joi.string()
     .valid(...Object.values(Loglevel))
diff --git a/src/frontend-config/frontend-config.service.spec.ts b/src/frontend-config/frontend-config.service.spec.ts
index 83bc38b9f..05d06ba53 100644
--- a/src/frontend-config/frontend-config.service.spec.ts
+++ b/src/frontend-config/frontend-config.service.spec.ts
@@ -21,6 +21,7 @@ import { Loglevel } from '../config/loglevel.enum';
  */
 
 describe('FrontendConfigService', () => {
+  const domain = 'http://md.example.com';
   const emptyAuthConfig: AuthConfig = {
     email: {
       enableLogin: false,
@@ -183,8 +184,8 @@ describe('FrontendConfigService', () => {
                         ]) {
                           it(`combination #${index} works`, async () => {
                             const appConfig: AppConfig = {
-                              domain: 'http://md.example.com',
-                              rendererOrigin: renderOrigin,
+                              domain: domain,
+                              rendererOrigin: renderOrigin ?? domain,
                               port: 3000,
                               loglevel: Loglevel.ERROR,
                               forbiddenNoteIds: [],
diff --git a/src/frontend-config/frontend-config.service.ts b/src/frontend-config/frontend-config.service.ts
index 1236ce1ff..a29448ebd 100644
--- a/src/frontend-config/frontend-config.service.ts
+++ b/src/frontend-config/frontend-config.service.ts
@@ -129,9 +129,7 @@ export class FrontendConfigService {
   private getIframeCommunication(): IframeCommunicationDto {
     return {
       editorOrigin: new URL(this.appConfig.domain),
-      rendererOrigin: this.appConfig.rendererOrigin
-        ? new URL(this.appConfig.rendererOrigin)
-        : new URL(this.appConfig.domain),
+      rendererOrigin: new URL(this.appConfig.rendererOrigin),
     };
   }
 }