diff --git a/modules/mailserver.nix b/modules/mailserver.nix
index 7fb0363..3392697 100644
--- a/modules/mailserver.nix
+++ b/modules/mailserver.nix
@@ -66,7 +66,7 @@ in {
     ];
     dnsBlacklistOverrides = ''
       balsoft.ru OK
-      ${builtins.concatStringsSep "OK \n" (builtins.attrNames config.devices)} OK
+      ${builtins.concatStringsSep " OK \n" (builtins.attrNames config.devices)} OK
       192.168.0.0/16 OK
     '';
   };