diff --git a/bricks/popup.js b/bricks/popup.js
index a148821..2ac4123 100644
--- a/bricks/popup.js
+++ b/bricks/popup.js
@@ -13,7 +13,7 @@ bricks.Popup = class extends bricks.VBox {
 		super(opts);
 		this.auto_task = null;
 		this.issub = false;
-		this.set_css('popup');
+		this.set_css('modal');
 		const zindex = bricks.app.new_zindex();
 		this.set_style('zIndex', zindex);
 		if (this.auto_dismiss){