diff --git a/src/config/Config.ts b/src/config/Config.ts
index 941ffc82..972c9e0c 100644
--- a/src/config/Config.ts
+++ b/src/config/Config.ts
@@ -5,6 +5,8 @@ SPDX-License-Identifier: AGPL-3.0-only
 Please see LICENSE in the repository root for full details.
 */
 
+import { merge } from "lodash";
+
 import { getUrlParams } from "../UrlParams";
 import {
   DEFAULT_CONFIG,
@@ -15,7 +17,7 @@ import {
 export class Config {
   private static internalInstance: Config | undefined;
 
-  public static get(): ConfigOptions {
+  public static get(): ResolvedConfigOptions {
     if (!this.internalInstance?.config)
       throw new Error("Config instance read before config got initialized");
     return this.internalInstance.config;
@@ -29,7 +31,7 @@ export class Config {
       Config.internalInstance.initPromise = downloadConfig(
         "../config.json",
       ).then((config) => {
-        internalInstance.config = { ...DEFAULT_CONFIG, ...config };
+        internalInstance.config = merge({}, DEFAULT_CONFIG, config);
       });
     }
     return Config.internalInstance.initPromise;
diff --git a/src/config/ConfigOptions.ts b/src/config/ConfigOptions.ts
index 2fd264ab..4f1ed02a 100644
--- a/src/config/ConfigOptions.ts
+++ b/src/config/ConfigOptions.ts
@@ -77,6 +77,17 @@ export interface ConfigOptions {
    * A link to the end-user license agreement (EULA)
    */
   eula: string;
+
+  media_devices?: {
+    /**
+     * Defines whether participants should start with audio enabled by default.
+     */
+    enable_audio?: boolean;
+    /**
+     * Defines whether participants should start with video enabled by default.
+     */
+    enable_video?: boolean;
+  };
 }
 
 // Overrides members from ConfigOptions that are always provided by the
@@ -88,6 +99,10 @@ export interface ResolvedConfigOptions extends ConfigOptions {
       server_name: string;
     };
   };
+  media_devices: {
+    enable_audio: boolean;
+    enable_video: boolean;
+  };
 }
 
 export const DEFAULT_CONFIG: ResolvedConfigOptions = {
@@ -98,4 +113,8 @@ export const DEFAULT_CONFIG: ResolvedConfigOptions = {
     },
   },
   eula: "https://static.element.io/legal/online-EULA.pdf",
+  media_devices: {
+    enable_audio: true,
+    enable_video: true,
+  },
 };
diff --git a/src/room/MuteStates.ts b/src/room/MuteStates.ts
index 80723f01..261be59e 100644
--- a/src/room/MuteStates.ts
+++ b/src/room/MuteStates.ts
@@ -18,6 +18,7 @@ import { logger } from "matrix-js-sdk/src/logger";
 import { MediaDevice, useMediaDevices } from "../livekit/MediaDevicesContext";
 import { useReactiveState } from "../useReactiveState";
 import { ElementWidgetActions, widget } from "../widget";
+import { Config } from "../config/Config";
 
 /**
  * If there already are this many participants in the call, we automatically mute
@@ -71,8 +72,14 @@ function useMuteState(
 export function useMuteStates(): MuteStates {
   const devices = useMediaDevices();
 
-  const audio = useMuteState(devices.audioInput, () => true);
-  const video = useMuteState(devices.videoInput, () => true);
+  const audio = useMuteState(
+    devices.audioInput,
+    () => Config.get().media_devices.enable_audio,
+  );
+  const video = useMuteState(
+    devices.videoInput,
+    () => Config.get().media_devices.enable_video,
+  );
 
   useEffect(() => {
     widget?.api.transport
diff --git a/src/rtcSessionHelper.test.ts b/src/rtcSessionHelper.test.ts
index 8a428661..5a5b7413 100644
--- a/src/rtcSessionHelper.test.ts
+++ b/src/rtcSessionHelper.test.ts
@@ -10,6 +10,7 @@ import { expect, test, vi } from "vitest";
 
 import { enterRTCSession } from "../src/rtcSessionHelpers";
 import { Config } from "../src/config/Config";
+import { DEFAULT_CONFIG } from "./config/ConfigOptions";
 
 test("It joins the correct Session", async () => {
   const focusFromOlderMembership = {
@@ -34,8 +35,8 @@ test("It joins the correct Session", async () => {
   };
 
   vi.spyOn(Config, "get").mockReturnValue({
+    ...DEFAULT_CONFIG,
     livekit: { livekit_service_url: "http://my-default-service-url.com" },
-    eula: "",
   });
   const mockedSession = vi.mocked({
     room: {