diff --git a/nix/modules/default/gw-sharding.nix b/nix/modules/default/gw-sharding.nix
index 033826780..a950f7a4e 100644
--- a/nix/modules/default/gw-sharding.nix
+++ b/nix/modules/default/gw-sharding.nix
@@ -39,7 +39,7 @@ in
                 # things we set by default...
                 EVENT_TRANSMISSION = "unix";
                 EVENT_SOCKET_PATH = "/run/spacebar/";
-                WORKER_NAME = "sb-gateway-${port}";
+                WORKER_NAME = "sb-gateway-${toString port}";
               }
               // cfg.extraEnvironment
               // {