diff --git a/module.nix b/module.nix
index 5260b42..cb6d408 100644
--- a/module.nix
+++ b/module.nix
@@ -76,7 +76,7 @@ in
         serviceConfig = {
           User = conf.user;
           Group = conf.group;
-          ExecStart = "${cfg.package}/bin/tsns";
+          ExecStart = "${cfg.package}/bin/tsns -d ${conf.dataDir}";
         };
       })
       enabledServers;