diff --git a/backup.nix b/backup.nix
index 4009b3f..6e136e5 100644
--- a/backup.nix
+++ b/backup.nix
@@ -117,7 +117,7 @@ in {
 
     script = ''
       invocationId="$(systemctl show --value -p InvocationID misskey-backup.service)"
-      logs="$(journalctl _SYSTEMD_INVOCATION_ID= -u misskey-backup.service)"
+      logs="$(journalctl _SYSTEMD_INVOCATION_ID="$invocationId" -u misskey-backup.service)"
 
       ${notifyErrorPkg}/bin/notify-error "backup" "Misskey Backup Failure Notification" "$(cat <<EOMSG
       A backup process has failed. Logs to follow: