diff --git a/demo/shapes-in-a-canvas.html b/demo/shapes-in-a-canvas.html
index 34e1202..f6a6ed9 100644
--- a/demo/shapes-in-a-canvas.html
+++ b/demo/shapes-in-a-canvas.html
@@ -6,7 +6,10 @@
     <title>Shapes</title>
     <style>
       html {
+        width: 100%;
         height: 100%;
+        position: fixed;
+        overflow: hidden;
       }
 
       body {