diff --git a/docs/assets/example/index.js b/docs/assets/example/index.js
index b8979e515..f63db8b51 100644
--- a/docs/assets/example/index.js
+++ b/docs/assets/example/index.js
@@ -51,7 +51,7 @@ var art = new Artplayer({
     ],
     layers: [
         {
-            html: `<img style="width: 100px" src="/assets/sample/layer.png">`,
+            html: '<img style="width: 100px" src="/assets/sample/layer.png">',
             click: function () {
                 console.info('You clicked on the custom layer');
             },