diff --git a/nixos/modules/services/web-apps/nextcloud.nix b/nixos/modules/services/web-apps/nextcloud.nix
index b40abf5e615b..b9186a1dc07f 100644
--- a/nixos/modules/services/web-apps/nextcloud.nix
+++ b/nixos/modules/services/web-apps/nextcloud.nix
@@ -532,6 +532,7 @@ in {
               add_header X-Download-Options noopen;
               add_header X-Permitted-Cross-Domain-Policies none;
               add_header Referrer-Policy no-referrer;
+              add_header Strict-Transport-Security "max-age=15552000; includeSubDomains" always;
               error_page 403 /core/templates/403.php;
               error_page 404 /core/templates/404.php;
               client_max_body_size ${cfg.maxUploadSize};