diff --git a/system/nixos/mastodon.nix b/system/nixos/mastodon.nix
index e72a6d9..7c6d3ea 100644
--- a/system/nixos/mastodon.nix
+++ b/system/nixos/mastodon.nix
@@ -119,7 +119,7 @@ in
       add_header Access-Control-Allow-Origin https://mastodon.kempkens.io;
 
       if ($ssl_protocol != "") {
-        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload";
+        add_header Strict-Transport-Security max-age=31536000\;\ includeSubDomains\;\ preload;
       }
     '';