diff --git a/backup.nix b/backup.nix
index fb7ec9e..c8efb3f 100644
--- a/backup.nix
+++ b/backup.nix
@@ -67,7 +67,7 @@ in
         RandomizedDelaySec = cfg.randomized-delay;
       };
     };
-    systemd.timers."backup-helper@etc-machine\x2did" = {
+    systemd.timers."backup-helper@/etc/machine-id" = {
       wantedBy = [ "timers.target" ];
       overrideStrategy = "asDropin";
     };