diff --git a/index.html b/index.html
index 70a707a..573faf4 100644
--- a/index.html
+++ b/index.html
@@ -2,6 +2,7 @@
 <html>
 	<head>
 		<meta charset="utf-8">
+		<meta http-equiv="Content-Security-Policy" content="default-src 'self'; frame-src 'none'; object-src 'none'; connect-src *;">
 		<title>gamja IRC client</title>
 		<link rel="stylesheet" href="./style.css">
 		<script type="module" src="./main.js"></script>
