diff --git a/nixos/modules/misc/ids.nix b/nixos/modules/misc/ids.nix
index b958922c0e47..c22075de1c93 100644
--- a/nixos/modules/misc/ids.nix
+++ b/nixos/modules/misc/ids.nix
@@ -220,7 +220,7 @@ in
       zope2 = 185;
       ripple-data-api = 186;
       mediatomb = 187;
-      rdnssd = 188;
+      #rdnssd = 188; #dynamically allocated as of 2021-09-18
       ihaskell = 189;
       i2p = 190;
       lambdabot = 191;
diff --git a/nixos/modules/services/networking/rdnssd.nix b/nixos/modules/services/networking/rdnssd.nix
index 469504c43172..fd04bb8108f0 100644
--- a/nixos/modules/services/networking/rdnssd.nix
+++ b/nixos/modules/services/networking/rdnssd.nix
@@ -72,8 +72,10 @@ in
 
     users.users.rdnssd = {
       description = "RDNSSD Daemon User";
-      uid = config.ids.uids.rdnssd;
+      isSystemUser = true;
+      group = "rdnssd";
     };
+    users.groups.rdnssd = {};
 
   };