diff --git a/packages/sdk/src/client/client.ts b/packages/sdk/src/client/client.ts
index aa406ed40..bae869c59 100644
--- a/packages/sdk/src/client/client.ts
+++ b/packages/sdk/src/client/client.ts
@@ -43,6 +43,7 @@ import { OpSource } from '@yorkie-js-sdk/src/document/operation/operation';
 import { createAuthInterceptor } from '@yorkie-js-sdk/src/client/auth_interceptor';
 import { createMetricInterceptor } from '@yorkie-js-sdk/src/client/metric_interceptor';
 import { validateSerializable } from '../util/validator';
+import { Json } from '@yorkie-js-sdk/src/document/document';
 
 /**
  * `SyncMode` defines synchronization modes for the PushPullChanges API.
@@ -607,7 +608,7 @@ export class Client {
   public broadcast(
     docKey: DocumentKey,
     topic: string,
-    payload: any,
+    payload: Json,
   ): Promise<void> {
     if (!this.isActive()) {
       throw new YorkieError(
diff --git a/packages/sdk/src/devtools/types.ts b/packages/sdk/src/devtools/types.ts
index 87edebd57..7cf2efd89 100644
--- a/packages/sdk/src/devtools/types.ts
+++ b/packages/sdk/src/devtools/types.ts
@@ -17,20 +17,7 @@
 import type { PrimitiveValue } from '@yorkie-js-sdk/src/document/crdt/primitive';
 import type { CRDTTreePosStruct } from '@yorkie-js-sdk/src/document/crdt/tree';
 import { CounterValue } from '@yorkie-js-sdk/src/document/crdt/counter';
-
-/**
- * `Json` represents a JSON value.
- *
- * TODO(hackerwins): We need to replace `Indexable` with `Json`.
- */
-export type Json =
-  | string
-  | number
-  | boolean
-  // eslint-disable-next-line @typescript-eslint/ban-types
-  | null
-  | { [key: string]: Json }
-  | Array<Json>;
+import { Json } from '@yorkie-js-sdk/src/document/document';
 
 /**
  * `Client` represents a client value in devtools.
diff --git a/packages/sdk/src/document/document.ts b/packages/sdk/src/document/document.ts
index 82ffae048..056b3e4b0 100644
--- a/packages/sdk/src/document/document.ts
+++ b/packages/sdk/src/document/document.ts
@@ -385,7 +385,7 @@ export interface PresenceChangedEvent<P extends Indexable>
 
 export interface BroadcastEvent extends BaseDocEvent {
   type: DocEventType.Broadcast;
-  value: { clientID: ActorID; topic: string; payload: any };
+  value: { clientID: ActorID; topic: string; payload: Json };
   error?: ErrorFn;
 }
 
@@ -420,7 +420,7 @@ export type DocEventTopic = keyof DocEventCallbackMap<never>;
 export type DocEventCallback<P extends Indexable> =
   DocEventCallbackMap<P>[DocEventTopic];
 
-type Json = JsonScalar | JsonArray | JsonObject;
+export type Json = JsonScalar | JsonArray | JsonObject;
 
 // eslint-disable-next-line @typescript-eslint/ban-types
 type JsonScalar = string | number | boolean | null;
@@ -2065,7 +2065,7 @@ export class Document<T, P extends Indexable = Indexable> {
   /**
    * `broadcast` the payload to the given topic.
    */
-  public broadcast(topic: string, payload: any, error?: ErrorFn) {
+  public broadcast(topic: string, payload: Json, error?: ErrorFn) {
     const broadcastEvent: LocalBroadcastEvent = {
       type: DocEventType.LocalBroadcast,
       value: { topic, payload },
diff --git a/packages/sdk/src/util/validator.ts b/packages/sdk/src/util/validator.ts
index 33625d837..0d57912f3 100644
--- a/packages/sdk/src/util/validator.ts
+++ b/packages/sdk/src/util/validator.ts
@@ -17,7 +17,7 @@
 /**
  * `validateSerializable` returns whether the given value is serializable or not.
  */
-export const validateSerializable = (value: any): boolean => {
+export const validateSerializable = (value: unknown): boolean => {
   try {
     const serialized = JSON.stringify(value);
 
diff --git a/packages/sdk/test/integration/client_test.ts b/packages/sdk/test/integration/client_test.ts
index 004e0b506..2d485e386 100644
--- a/packages/sdk/test/integration/client_test.ts
+++ b/packages/sdk/test/integration/client_test.ts
@@ -900,6 +900,8 @@ describe.sequential('Client', function () {
       eventCollector.add(error.message);
     };
 
+    // @ts-ignore
+    // Disable type checking for testing purposes
     doc.broadcast(broadcastTopic, payload, errorHandler);
 
     await eventCollector.waitAndVerifyNthEvent(1, broadcastErrMessage);