diff --git a/lib/template.html b/lib/template.html
index 981aa9ac..375a92fe 100755
--- a/lib/template.html
+++ b/lib/template.html
@@ -46,6 +46,7 @@
 {% if page.date %}
   <meta property="og:type" content="article" />
   <meta property="article:published_time" content="{{ page.date | date_to_xmlschema }}" />
+  <meta property="article:modified_time" content="{{ page.updated | default: page.date | date_to_xmlschema }}"/>
 {% else %}
   <meta property="og:type" content="website" />
 {% endif %}