diff --git a/__mocks__/matrix-js-sdk.js b/__mocks__/matrix-js-sdk.js
index 508557e..8942117 100644
--- a/__mocks__/matrix-js-sdk.js
+++ b/__mocks__/matrix-js-sdk.js
@@ -157,6 +157,10 @@ export const mockGetGroupUsers = jest.fn(() => {
 
 export const mockGetUser = jest.fn().mockReturnValue({ presence: 'online'});
 
+export const mockSendStateEvent = jest.fn(() => {
+  return Promise.resolve();
+});
+
 export const mockClient = {
   registerRequest: mockRegisterRequest,
   initCrypto: mockInitCrypto,
@@ -186,6 +190,7 @@ export const mockClient = {
   getJoinedRoomMembers: mockGetJoinedRoomMembers,
   getUser: mockGetUser,
   getGroupUsers: mockGetGroupUsers,
+  sendStateEvent: mockSendStateEvent,
 }
 
 export const WebStorageSessionStore = jest.fn()
diff --git a/src/bot.test.js b/src/bot.test.js
index c312908..24a6148 100644
--- a/src/bot.test.js
+++ b/src/bot.test.js
@@ -32,7 +32,8 @@ import {
   mockKick,
   mockGetJoinedRoomMembers,
   mockGetUser,
-  mockGetGroupUsers
+  mockGetGroupUsers,
+  mockSendStateEvent,
 } from "matrix-js-sdk";
 
 import OcrccBot from './bot'
@@ -100,6 +101,7 @@ describe('OcrccBot', () => {
     mockSendTextMessage.mockClear()
     mockAppendFileSync.mockClear()
     mockGetGroupUsers.mockClear()
+    mockSendStateEvent.mockClear()
   })
 
 
@@ -325,4 +327,17 @@ describe('OcrccBot', () => {
       expect(mockStartClient).toHaveBeenCalled()
     })
   })
+
+  test('#sendBotSignal should send custom state event', () => {
+    const bot = new OcrccBot(botConfig)
+    bot.start()
+    const test_room_id = 'test_room_id'
+    const signal = 'END_CHAT'
+
+    bot.sendBotSignal(test_room_id, signal)
+
+    waitForExpect(() => {
+      expect(mockSendStateEvent).toHaveBeenCalledWith(test_room_id, 'm.bot.signal', { signal })
+    })
+  })
 })
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