diff --git a/src/UrlParams.test.ts b/src/UrlParams.test.ts
index 75bf9bfb8..3a61a76b9 100644
--- a/src/UrlParams.test.ts
+++ b/src/UrlParams.test.ts
@@ -16,12 +16,15 @@ import {
   HeaderStyle,
   getUrlParams,
 } from "../src/UrlParams";
+import { mockConfig } from "./utils/test";
 
 const ROOM_NAME = "roomNameHere";
 const ROOM_ID = "!d45f138fsd";
 const ORIGIN = "https://call.element.io";
 const HOMESERVER = "localhost";
 
+mockConfig();
+
 describe("UrlParams", () => {
   describe("handles URL with /room/", () => {
     it("and nothing else", () => {
diff --git a/src/config/ConfigOptions.ts b/src/config/ConfigOptions.ts
index 3d9fcfb50..ff0aadc37 100644
--- a/src/config/ConfigOptions.ts
+++ b/src/config/ConfigOptions.ts
@@ -183,12 +183,6 @@ export interface ConfigOptions {
 // Overrides members from ConfigOptions that are always provided by the
 // default config and are therefore non-optional.
 export interface ResolvedConfigOptions extends ConfigOptions {
-  default_server_config: {
-    ["m.homeserver"]: {
-      base_url: string;
-      server_name: string;
-    };
-  };
   sync_disconnect_grace_period_ms: number;
   ssla: string;
   matrix_rtc_session: {
@@ -202,12 +196,6 @@ export interface ResolvedConfigOptions extends ConfigOptions {
 }
 
 export const DEFAULT_CONFIG: ResolvedConfigOptions = {
-  default_server_config: {
-    ["m.homeserver"]: {
-      base_url: "http://localhost:8008",
-      server_name: "localhost",
-    },
-  },
   features: {
     feature_use_device_session_member_events: true,
   },
diff --git a/src/utils/test.ts b/src/utils/test.ts
index 695dd0462..206db88f5 100644
--- a/src/utils/test.ts
+++ b/src/utils/test.ts
@@ -439,6 +439,12 @@ export function mockConfig(
   const spy = vi.spyOn(Config, "get").mockReturnValue({
     ...DEFAULT_CONFIG,
     ...config,
+    default_server_config: {
+      ["m.homeserver"]: {
+        base_url: "http://localhost:8008",
+        server_name: "localhost",
+      },
+    },
   });
   // simulate loading the config
   vi.spyOn(Config, "init").mockResolvedValue(void 0);