diff --git a/demo/src/index.ejs b/demo/src/index.ejs
index ba3197c..7cd5e26 100644
--- a/demo/src/index.ejs
+++ b/demo/src/index.ejs
@@ -42,7 +42,7 @@
         display: none;
       }
 
-      .matter-js.dev.matter-demo canvas {
+      .matter-js.dev.comparing.matter-demo canvas {
         background: transparent !important;
         z-index: 20;
       }