diff --git a/book.toml b/book.toml
index 8f329a7..4ed03cb 100644
--- a/book.toml
+++ b/book.toml
@@ -1,9 +1,10 @@
 [book]
+authors = ["Kohei Watanabe"]
 language = "ja"
 title = "Node.jsを使う"
-authors = ["Kohei Watanabe"]
 
 [output.html]
-site-url = "/nodejs-hands-on/"
-git-repository-url = "https://github.com/kou029w/nodejs-hands-on"
+additional-js = ["external-links.js", "regexp-search.js"]
 edit-url-template = "https://github.com/kou029w/nodejs-hands-on/edit/main/{path}"
+git-repository-url = "https://github.com/kou029w/nodejs-hands-on"
+site-url = "/nodejs-hands-on/"
diff --git a/external-links.js b/external-links.js
new file mode 100644
index 0000000..97590dc
--- /dev/null
+++ b/external-links.js
@@ -0,0 +1,13 @@
+"use strict";
+
+// 外部リンクを新しいブラウザーコンテキストで開く
+window.addEventListener("DOMContentLoaded", () => {
+  const selector = ["http:", "https:"]
+    .map((scheme) => `a[href^="${scheme}"]`)
+    .join(",");
+
+  document.querySelectorAll(selector).forEach((a) => {
+    a.target = "_blank";
+    a.rel = "noreferrer";
+  });
+});
diff --git a/regexp-search.js b/regexp-search.js
new file mode 100644
index 0000000..46e45f4
--- /dev/null
+++ b/regexp-search.js
@@ -0,0 +1,16 @@
+"use strict";
+
+// 正規表現検索を有効化
+window.elasticlunr.Index.load = (index) => ({
+  search(keyword) {
+    const regexp = new RegExp(keyword, "gi");
+
+    return [...Object.entries(index.documentStore.docs)].flatMap(
+      ([ref, doc]) => {
+        const match = `${doc.title} ${doc.body}`.match(regexp);
+
+        return match ? [{ ref, doc, score: match.length }] : [];
+      },
+    );
+  },
+});