diff --git a/src/main/java/org/ntlab/tampoposerver/resources/ChatRequestsResource.java b/src/main/java/org/ntlab/tampoposerver/resources/ChatRequestsResource.java
index 3c8cd02..a41e833 100644
--- a/src/main/java/org/ntlab/tampoposerver/resources/ChatRequestsResource.java
+++ b/src/main/java/org/ntlab/tampoposerver/resources/ChatRequestsResource.java
@@ -68,6 +68,7 @@
     //トークンを使って他人の情報を返さないように実装する。
     @POST
     @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
+    @Produces(MediaType.TEXT_PLAIN)
     public Response postChatRequest(
            @FormParam("token") String token,
            @FormParam("sender-id") String senderId,