diff --git a/docs/2-browser-apps/06-project/_samples/todo/script.js b/docs/2-browser-apps/06-project/_samples/todo/script.js
index c40ec45f4..15a23597e 100644
--- a/docs/2-browser-apps/06-project/_samples/todo/script.js
+++ b/docs/2-browser-apps/06-project/_samples/todo/script.js
@@ -2,7 +2,9 @@ const todoList = document.getElementById("todo-list");
 const todoInput = document.getElementById("todo-input");
 const addButton = document.getElementById("add-button");
 
-todoInput.oninput = () => (addButton.disabled = todoInput === "");
+todoInput.oninput = () => {
+  addButton.disabled = todoInput.value === "";
+};
 
 addButton.onclick = () => {
   const todoItem = document.createElement("li");
diff --git a/docs/2-browser-apps/06-project/index.mdx b/docs/2-browser-apps/06-project/index.mdx
index f4d1d901c..f05569c16 100644
--- a/docs/2-browser-apps/06-project/index.mdx
+++ b/docs/2-browser-apps/06-project/index.mdx
@@ -271,7 +271,7 @@ addButton.onclick = () => {
   addButton.disabled = true; // valueへの代入はoninputイベントを発火しない
   editButton.textContent = "編集";
   editButton.onclick = () => {
-    const input = prompt("新しい内容を入力してください"。);
+    const input = prompt("新しい内容を入力してください。");
     // prompt関数は入力された文字列が空の場合は空文字列 ("")、キャンセルされた場合はnullを返す
     if (input !== "" && input !== null) todoText.textContent = input;
   };