diff --git a/_includes/nav-header.html b/_includes/nav-header.html
index 1ebbaef139ecff27edc065b6714d02b945a203d9..12c13ae9ddb10aa849544ddc117e7e87d331948f 100644
--- a/_includes/nav-header.html
+++ b/_includes/nav-header.html
@@ -57,3 +57,5 @@ applyToggle('.list--nav', '.button', 640)
 
 <!-- UI JS file -->
 <script src="{{site.baseurl}}/assets/scripts/photoswipe-ui-default.min.js"></script>
+
+<meta property="og:image:type" content="image/jpeg">