diff --git a/web-vr/hello-world/demo/demo.js b/web-vr/hello-world/demo/demo.js
index 538bc587fb..136bfb12f9 100644
--- a/web-vr/hello-world/demo/demo.js
+++ b/web-vr/hello-world/demo/demo.js
@@ -75,7 +75,7 @@ class Demo {
     this._aspect = this._width / this._height;
 
     this._renderer.setSize(this._width, this._height);
-
+    this._renderer.setPixelRatio(window.devicePixelRatio);
     if (!this._camera) {
       return;
     }
@@ -138,4 +138,4 @@ class Demo {
     this._scene.add(this._box);
     this._scene.add(room);
   }
-}
\ No newline at end of file
+}