diff --git a/nixos/modules/services/misc/tzupdate.nix b/nixos/modules/services/misc/tzupdate.nix
index e9f086a2ad78..9e979bb47675 100644
--- a/nixos/modules/services/misc/tzupdate.nix
+++ b/nixos/modules/services/misc/tzupdate.nix
@@ -30,13 +30,12 @@ in {
       description = "tzupdate timezone update service";
       wants = [ "network-online.target" ];
       after = [ "network-online.target" ];
+      script = ''
+        timedatectl set-timezone $(${lib.getExe pkgs.tzupdate} --print-only)
+      '';
 
       serviceConfig = {
         Type = "oneshot";
-        # We could link directly into pkgs.tzdata, but at least timedatectl seems
-        # to expect the symlink to point directly to a file in etc.
-        # Setting the "debian timezone file" to point at /dev/null stops it doing anything.
-        ExecStart = "${pkgs.tzupdate}/bin/tzupdate -z /etc/zoneinfo -d /dev/null";
       };
     };
   };