diff --git a/index.html b/index.html
index e159600..c274ecb 100644
--- a/index.html
+++ b/index.html
@@ -227,6 +227,7 @@ The light is on. The room is empty."
     <script src="js/data.js"></script>
     <script src="js/utils.js"></script>
     <script src="js/strategy.js"></script>
+    <script src="js/sound.js"></script>
     <script src="js/engine.js"></script>
     <script src="js/render.js"></script>
     <script src="js/main.js"></script>