diff --git a/core-overlay.html b/core-overlay.html
index 2c7c3d8..7165ce5 100644
--- a/core-overlay.html
+++ b/core-overlay.html
@@ -70,7 +70,7 @@ <h2>Dialog</h2>
 
 @event core-overlay-open
 @param {Object} detail
-@param {Object} detail.opened the opened state
+@param {Object} detail the opened state
 -->
 <!--
 Fired when the `core-overlay` has completely opened.