diff --git a/hosts/hetzner-arm/profiles/photoprism.nix b/hosts/hetzner-arm/profiles/photoprism.nix
index 4a0ee6c..b8ae18e 100644
--- a/hosts/hetzner-arm/profiles/photoprism.nix
+++ b/hosts/hetzner-arm/profiles/photoprism.nix
@@ -54,7 +54,7 @@ in {
     enableACME = true;
     locations = {
       "/" = {
-        proxyPass = "http://127.0.0.1:${config.services.photoprism.port}";
+        proxyPass = "http://127.0.0.1:${toString config.services.photoprism.port}";
         proxyWebsockets = true;
         extraConfig = ''
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;