diff --git a/build.gradle.kts b/build.gradle.kts
index 266a6f8..5f5ee64 100755
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,7 +1,7 @@
 import com.github.breadmoirai.githubreleaseplugin.GithubReleaseTask
 
 group = "com.cjcrafter"
-version = "2.1.0"
+version = "2.1.1"
 
 plugins {
 `java-library`
diff --git a/src/main/kotlin/com/cjcrafter/openai/chat/ChatResponseFormat.kt b/src/main/kotlin/com/cjcrafter/openai/chat/ChatResponseFormat.kt
index 0b4b5df..22e0f53 100755
--- a/src/main/kotlin/com/cjcrafter/openai/chat/ChatResponseFormat.kt
+++ b/src/main/kotlin/com/cjcrafter/openai/chat/ChatResponseFormat.kt
@@ -2,10 +2,10 @@ package com.cjcrafter.openai.chat
 
 import com.fasterxml.jackson.annotation.JsonProperty
 
-class ChatResponseFormat {
+class ChatResponseFormat(@JsonProperty("type") val type: Type = Type.TEXT) {
 
 enum class Type {
- @JsonProperty("json")
+ @JsonProperty("json_object")
 JSON,
 @JsonProperty("text")
 TEXT
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://patch-diff.githubusercontent.com/raw/CJCrafter/ChatGPT-Java-API/pull/51.diff">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://patch-diff.githubusercontent.com/raw/CJCrafter/ChatGPT-Java-API/pull/51.diff" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>