diff --git a/bundles/backup-server/files/rotate-single-backup-client b/bundles/backup-server/files/rotate-single-backup-client
index ee49e26..c76c6b5 100644
--- a/bundles/backup-server/files/rotate-single-backup-client
+++ b/bundles/backup-server/files/rotate-single-backup-client
@@ -33,12 +33,11 @@ for line in check_output('LC_ALL=C zfs list -H -t snapshot -o name', shell=True)
 
     if line.startswith('{}/{}@'.format(server_settings['zfs-base'], NODE)):
         _, snapname = line.split('@', 1)
+        ts, bucket = snapname.split('-', 1)
 
-        if 'zfs-auto-snap' in snapname:
-            # migration from auto-snapshots, ignore
+        if not ts.isdigit():
             continue
 
-        ts, bucket = snapname.split('-', 1)
         buckets.setdefault(bucket, set()).add(int(ts))
         syslog(f'classified {line} as {bucket} from {ts}')