diff --git a/data/conf/nginx/site.conf b/data/conf/nginx/site.conf
index d00ff7782..67d6f1a11 100644
--- a/data/conf/nginx/site.conf
+++ b/data/conf/nginx/site.conf
@@ -30,7 +30,7 @@ server {
   ssl_session_timeout 1d;
   ssl_session_tickets off;
 
-  add_header Strict-Transport-Security "max-age=15768000; includeSubDomains";
+  add_header Strict-Transport-Security "max-age=15768000;";
   add_header X-Content-Type-Options nosniff;
   add_header X-XSS-Protection "1; mode=block";
   add_header X-Robots-Tag none;