diff --git a/pp-node-exporter.nix b/pp-node-exporter.nix
index bacb1ac..3bf31a5 100644
--- a/pp-node-exporter.nix
+++ b/pp-node-exporter.nix
@@ -6,19 +6,16 @@ let
     text = cfg.prometheusCa;
   };
   yaml = pkgs.formats.yaml { };
-  nodeWebConfig = yaml.generate "prometheus-node-exporter-webconfig.yml" (lib.mkMerge [
-    ({
+  nodeWebConfig = yaml.generate "prometheus-node-exporter-webconfig.yml" {
       tls_server_config = {
         client_ca_file = prometheusCaFile;
         cert_file = cfg.prometheusNodeExporterCertFile;
         key_file = cfg.prometheusNodeExporterCertKeyFile;
         client_auth_type = "RequireAndVerifyClientCert";
-      };
-    })
-    (lib.mkIf (cfg.prometheusNodeExporterAllowScrapperSans != null) {
-      tls_server_config.client_allowed_sans = cfg.prometheusNodeExporterAllowScrapperSans;
-    })
-  ]);
+      } // (if (cfg.prometheusNodeExporterAllowScrapperSans != null) then {
+        client_allowed_sans = cfg.prometheusNodeExporterAllowScrapperSans;
+      } else {});
+  };
 in {
   options.services.ppNodeExporter = {
     prometheusCa = lib.mkOption {