diff --git a/src/components/entity/state-info.html b/src/components/entity/state-info.html
index 36a2ed6c44..311fc189c6 100644
--- a/src/components/entity/state-info.html
+++ b/src/components/entity/state-info.html
@@ -44,7 +44,7 @@
 
         <template is='dom-if' if='[[inDialog]]'>
           <div class='time-ago'>
-            <ha-relative-time datetime-obj='[[stateObj.lastChangedAsDate]]'></ha-relative-time>
+            <ha-relative-time datetime='[[stateObj.last_changed]]'></ha-relative-time>
           </div>
         </template>