diff --git a/index.html b/index.html
index a096b2d..4ce699f 100644
--- a/index.html
+++ b/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="en">
+<html lang="en" xmlns:og="http://ogp.me/ns#">
 <head>
     <title></title>
     <meta charset="utf-8">
