diff --git a/src/index.html b/src/index.html
index 04bb7d5..3398d59 100644
--- a/src/index.html
+++ b/src/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html prefix="og: https://ogp.me/ns#" lang="de">
+<html prefix="og:https://ogp.me/ns#" lang="de">
 <head>
     <meta charset="utf-8">
     <title>Kindertagesstätten in Flensburg</title>
