diff --git a/feed.xml b/feed.xml
index faaead7c..19cb9cda 100644
--- a/feed.xml
+++ b/feed.xml
@@ -21,7 +21,7 @@ layout: none
   <title type="html"><![CDATA[{{ post.title | cdata_escape }}]]></title>
   <link rel="alternate" type="text/html" href="{{ site.url }}{{ post.url }}" />
   <id>{{ site.url }}{{ post.id }}</id>
-  {% if post.modified %}<updated>{{ post.modified | to_xmlschema }}</updated>
+  {% if post.modified %}<updated>{{ post.modified | to_xmlschema }}T00:00:00-00:00</updated>
   <published>{{ post.date | date_to_xmlschema }}</published>
   {% else %}<published>{{ post.date | date_to_xmlschema }}</published>
   <updated>{{ post.date | date_to_xmlschema }}</updated>{% endif %}