diff --git a/backend/src/main/java/org/example/backend/domain/question/service/ChatServiceImpl.java b/backend/src/main/java/org/example/backend/domain/question/service/ChatServiceImpl.java
index fe5d4920..36ae5b76 100644
--- a/backend/src/main/java/org/example/backend/domain/question/service/ChatServiceImpl.java
+++ b/backend/src/main/java/org/example/backend/domain/question/service/ChatServiceImpl.java
@@ -61,7 +61,7 @@ public void sendMessage(UUID lectureId, MessageRequestDTO.MessageDTO messageDTO,
             // 2. 메시지 전파
             // 메시지 구성
             MessageRequestDTO.MessageDTO maskMessage = MessageRequestDTO.MessageDTO.builder()
-                    .senderId(null)
+                    .senderId(userId)
                     .senderName(null)
                     .content(messageDTO.getContent())
                     .role(sender.getRole())