diff --git a/nixos/modules/services/networking/harmonia.nix b/nixos/modules/services/networking/harmonia.nix
index beaa7d00b6ce..d0f4a8a6e633 100644
--- a/nixos/modules/services/networking/harmonia.nix
+++ b/nixos/modules/services/networking/harmonia.nix
@@ -29,6 +29,11 @@ in
 
   config = lib.mkIf cfg.enable {
     nix.settings.extra-allowed-users = [ "harmonia" ];
+    users.users.harmonia = {
+      isSystemUser = true;
+      group = "harmonia";
+    };
+    users.groups.harmonia = { };
 
     systemd.services.harmonia = {
       description = "harmonia binary cache service";
@@ -50,7 +55,6 @@ in
         ExecStart = lib.getExe cfg.package;
         User = "harmonia";
         Group = "harmonia";
-        DynamicUser = true;
         PrivateUsers = true;
         DeviceAllow = [ "" ];
         UMask = "0066";