diff --git a/app/src/main/java/com/example/tampopo_client/resources/ChatroomResource.java b/app/src/main/java/com/example/tampopo_client/resources/ChatroomResource.java
index bc3f660..4ea005d 100644
--- a/app/src/main/java/com/example/tampopo_client/resources/ChatroomResource.java
+++ b/app/src/main/java/com/example/tampopo_client/resources/ChatroomResource.java
@@ -60,6 +60,7 @@
 
     //チャットルームにメッセージを追加する
     @POST("chat-rooms/{chatroom-id}/{user-id}/message")
+    @FormUrlEncoded
     Call<ChatMessage> sendMessage(
             @Path("chatroom-id") String chatRoomId,
             @Path("user-id") String senderId,