diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProviderTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProviderTest.java
index dd7c99cd9..ef8873bf1 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProviderTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProviderTest.java
@@ -28,6 +28,7 @@
 import java.util.Set;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.BDDMockito.willDoNothing;
@@ -173,6 +174,19 @@ class ChatWebSocketHandleTextMessageProviderTest extends ChatWebSocketHandleText
         assertThat(actual).hasSize(1);
     }
 
+    @Test
+    void 잘못된_데이터_타입_전달시_예외가_발생한다() throws JsonProcessingException {
+        // given
+        given(writerSession.getAttributes()).willReturn(발신자_세션_attribute_정보);
+        willDoNothing().given(sessions).add(writerSession, 채팅방.getId());
+        willReturn(false).given(sessions).containsByUserId(채팅방.getId(), 수신자.getId());
+        willReturn(Set.of(writerSession)).given(sessions).getSessionsByChatRoomId(채팅방.getId());
+
+        // when
+        assertThatThrownBy(() -> provider.handleCreateSendMessage(writerSession, 잘못된_메시지_전송_데이터))
+                .isInstanceOf(IllegalArgumentException.class);
+    }
+
     @Test
     void 세션을_삭제한다() {
         // given
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/fixture/ChatWebSocketHandleTextMessageProviderTestFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/fixture/ChatWebSocketHandleTextMessageProviderTestFixture.java
index 07aecd76e..a1fc31506 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/fixture/ChatWebSocketHandleTextMessageProviderTestFixture.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/handler/fixture/ChatWebSocketHandleTextMessageProviderTestFixture.java
@@ -46,6 +46,7 @@ public class ChatWebSocketHandleTextMessageProviderTestFixture {
     protected Map<String, Object> 발신자_세션_attribute_정보;
     protected Map<String, Object> 수신자_세션_attribute_정보;
     protected Map<String, String> 메시지_전송_데이터;
+    protected Map<String, String> 잘못된_메시지_전송_데이터;
 
     protected CreateReadMessageLogEvent 메시지_로그_생성_이벤트;
 
@@ -93,6 +94,9 @@ void setUpFixture() {
                 "receiverId", String.valueOf(수신자.getId()),
                 "contents", "메시지 내용"
         );
+        잘못된_메시지_전송_데이터 = Map.of(
+                "type", "wrong message type"
+        );
 
         메시지_로그_생성_이벤트 = new CreateReadMessageLogEvent(채팅방);
     }