diff --git a/docs/sample-project/index.html b/docs/sample-project/index.html
index 5ffd279..8954eeb 100644
--- a/docs/sample-project/index.html
+++ b/docs/sample-project/index.html
@@ -20,6 +20,7 @@
        <script src="../../src/graphics/graphics.js"></script>
        <script src="../../src/tween/easing.js"></script>
        <script src="../../src/tween/tween.js"></script>
+       <script src="../../src/physics/barnes-hut.js"></script>
        <script src="../../src/physics/atoms.js"></script>
        <script src="../../src/physics/physics.js"></script>
        <script src="../../src/physics/system.js"></script>