diff --git a/demo-minesweeper-polymer/src/main/java/com/vaadin/hummingbird/demo/minesweeper/component/MinesweeperUI.java b/demo-minesweeper-polymer/src/main/java/com/vaadin/hummingbird/demo/minesweeper/component/MinesweeperUI.java
index 0e138655b..a68087845 100644
--- a/demo-minesweeper-polymer/src/main/java/com/vaadin/hummingbird/demo/minesweeper/component/MinesweeperUI.java
+++ b/demo-minesweeper-polymer/src/main/java/com/vaadin/hummingbird/demo/minesweeper/component/MinesweeperUI.java
@@ -20,6 +20,7 @@
 import javax.servlet.annotation.WebServlet;
 
 import com.vaadin.annotations.VaadinServletConfiguration;
+import com.vaadin.annotations.WebComponents;
 import com.vaadin.hummingbird.demo.minesweeper.component.component.MinesweeperComponent;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.server.VaadinServlet;
@@ -30,6 +31,7 @@
  * UI which demonstrates how you can use the Hummingbird {@link Component} API
  * to create a Minesweeper game.
  */
+@WebComponents(1)
 public class MinesweeperUI extends UI {
 
     /**