diff --git a/html/index.html b/html/index.html
index 83f0012..f87ee7d 100644
--- a/html/index.html
+++ b/html/index.html
@@ -12,8 +12,10 @@
         }
     </script>
     <script id="fragmentShader" type="x-shader/x-fragment">
-        #ifdef GL_ES
+        #ifdef GL_FRAGMENT_PRECISION_HIGH
         precision highp float;
+        #else
+        precision mediump float;
         #endif
 
         uniform float iTime;
@@ -69,6 +71,10 @@
 <script type="module">
 			import * as THREE from 'https://unpkg.com/three/build/three.module.js';
 
+            window.requestAnimationFrame = window.requestAnimationFrame ||
+                               window.mozRequestAnimationFrame ||
+                               window.webkitRequestAnimationFrame ||
+                               window.msRequestAnimationFrame;
 			let camera, scene, renderer;
 			let uniforms;
 			let texture;
@@ -128,7 +134,7 @@
 
 
 			function animate() {
-				requestAnimationFrame( animate );
+				window.requestAnimationFrame( animate );
 				uniforms[ 'iTime' ].value = performance.now() / 1000;
 				renderer.render( scene, camera );
 			}