diff --git a/README.ja.md b/README.ja.md
index 9a4d3e6d..4c0532bb 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -10,9 +10,12 @@
 
 GitHub Actions 用のヘルパー
 
+## Table of Contents
+
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
-**Table of Contents**
+<details>
+<summary>Details</summary>
 
 - [使用方法](#%E4%BD%BF%E7%94%A8%E6%96%B9%E6%B3%95)
   - [Logger](#logger)
@@ -23,6 +26,7 @@ GitHub Actions 用のヘルパー
   - [ContextHelper](#contexthelper)
 - [Author](#author)
 
+</details>
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
 ## 使用方法
diff --git a/README.md b/README.md
index 6cbca706..ac6d9182 100644
--- a/README.md
+++ b/README.md
@@ -10,9 +10,12 @@
 
 Helper for GitHub Actions.
 
+## Table of Contents
+
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
-**Table of Contents**
+<details>
+<summary>Details</summary>
 
 - [Usage](#usage)
   - [Logger](#logger)
@@ -23,6 +26,7 @@ Helper for GitHub Actions.
   - [ContextHelper](#contexthelper)
 - [Author](#author)
 
+</details>
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
 ## Usage