diff --git a/Web-Browsers.md b/Web-Browsers.md
index ee13055..a6e7c6f 100644
--- a/Web-Browsers.md
+++ b/Web-Browsers.md
@@ -16,3 +16,7 @@ Then, open the below HTML on your HTTP server:
 NOTE: `file://` URL may not work with Ebiten. Execute your game on a HTTP server.
 
 If you want to embed your game into your web page, using iframe is strongly recommended.
+
+# Restrictions
+
+On iOS, touching is required to start sound. This is the browser's restriction.