diff --git a/my-element.html b/my-element.html
index 1e14ff0e..f65c3f09 100644
--- a/my-element.html
+++ b/my-element.html
@@ -11,6 +11,9 @@
 Polymer({
     is: 'my-element',
 
+    // Any property that’s part of your element’s public API should be declared in the properties object.
+    properties: {},
+
     // Fires when an instance of the element is created
     created: function() {},