diff --git a/frontend/src/api/common/api-request-builder/api-request-builder.ts b/frontend/src/api/common/api-request-builder/api-request-builder.ts
index ebcc5d6f2..920e24d1a 100644
--- a/frontend/src/api/common/api-request-builder/api-request-builder.ts
+++ b/frontend/src/api/common/api-request-builder/api-request-builder.ts
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
@@ -23,10 +23,11 @@ export abstract class ApiRequestBuilder<ResponseType> {
   /**
    * Initializes a new API call with the default request options.
    *
-   * @param endpoint The target endpoint without a leading slash.
+   * @param endpoint The target endpoint without a leading slash
+   * @param baseUrl An optional base URL that is used for the endpoint
    */
-  constructor(endpoint: string) {
-    this.targetUrl = `api/private/${endpoint}`
+  constructor(endpoint: string, baseUrl?: string) {
+    this.targetUrl = `${baseUrl ?? ''}api/private/${endpoint}`
   }
 
   protected async sendRequestAndVerifyResponse(httpMethod: RequestInit['method']): Promise<ApiResponse<ResponseType>> {
diff --git a/frontend/src/api/common/api-request-builder/delete-api-request-builder.spec.ts b/frontend/src/api/common/api-request-builder/delete-api-request-builder.spec.ts
index f44f38687..a98623ece 100644
--- a/frontend/src/api/common/api-request-builder/delete-api-request-builder.spec.ts
+++ b/frontend/src/api/common/api-request-builder/delete-api-request-builder.spec.ts
@@ -18,6 +18,12 @@ describe('DeleteApiRequestBuilder', () => {
   afterAll(() => {
     global.fetch = originalFetch
   })
+
+  it('uses the custom base url as prefix', async () => {
+    expectFetch('https://example.org/api/private/test', 200, { method: 'DELETE' })
+    await new DeleteApiRequestBuilder<string>('test', 'https://example.org/').sendRequest()
+  })
+
   describe('sendRequest without body', () => {
     it('without headers', async () => {
       expectFetch('api/private/test', 204, { method: 'DELETE' })
diff --git a/frontend/src/api/common/api-request-builder/get-api-request-builder.spec.ts b/frontend/src/api/common/api-request-builder/get-api-request-builder.spec.ts
index 17f40b2ed..5e08fb151 100644
--- a/frontend/src/api/common/api-request-builder/get-api-request-builder.spec.ts
+++ b/frontend/src/api/common/api-request-builder/get-api-request-builder.spec.ts
@@ -19,6 +19,11 @@ describe('GetApiRequestBuilder', () => {
     global.fetch = originalFetch
   })
 
+  it('uses the custom base url as prefix', async () => {
+    expectFetch('https://example.org/api/private/test', 200, { method: 'GET' })
+    await new GetApiRequestBuilder<string>('test', 'https://example.org/').sendRequest()
+  })
+
   describe('sendRequest', () => {
     it('without headers', async () => {
       expectFetch('api/private/test', 200, { method: 'GET' })
diff --git a/frontend/src/api/common/api-request-builder/post-api-request-builder.spec.ts b/frontend/src/api/common/api-request-builder/post-api-request-builder.spec.ts
index db145d9ad..f370b97dd 100644
--- a/frontend/src/api/common/api-request-builder/post-api-request-builder.spec.ts
+++ b/frontend/src/api/common/api-request-builder/post-api-request-builder.spec.ts
@@ -19,6 +19,11 @@ describe('PostApiRequestBuilder', () => {
     global.fetch = originalFetch
   })
 
+  it('uses the custom base url as prefix', async () => {
+    expectFetch('https://example.org/api/private/test', 200, { method: 'POST' })
+    await new PostApiRequestBuilder<string, undefined>('test', 'https://example.org/').sendRequest()
+  })
+
   describe('sendRequest without body', () => {
     it('without headers', async () => {
       expectFetch('api/private/test', 201, { method: 'POST' })
diff --git a/frontend/src/api/common/api-request-builder/put-api-request-builder.spec.ts b/frontend/src/api/common/api-request-builder/put-api-request-builder.spec.ts
index b4b8bcf6f..fc0e85d53 100644
--- a/frontend/src/api/common/api-request-builder/put-api-request-builder.spec.ts
+++ b/frontend/src/api/common/api-request-builder/put-api-request-builder.spec.ts
@@ -19,6 +19,11 @@ describe('PutApiRequestBuilder', () => {
     global.fetch = originalFetch
   })
 
+  it('uses the custom base url as prefix', async () => {
+    expectFetch('https://example.org/api/private/test', 200, { method: 'PUT' })
+    await new PutApiRequestBuilder<string, undefined>('test', 'https://example.org/').sendRequest()
+  })
+
   describe('sendRequest without body', () => {
     it('without headers', async () => {
       expectFetch('api/private/test', 200, { method: 'PUT' })