diff --git a/internal/rdb/inspect.go b/internal/rdb/inspect.go
index c213ab2..f18e800 100644
--- a/internal/rdb/inspect.go
+++ b/internal/rdb/inspect.go
@@ -546,38 +546,49 @@ func (r *RDB) ArchiveAllScheduledTasks(qname string) (int64, error) {
 	return r.removeAndArchiveAll(base.ScheduledKey(qname), base.ArchivedKey(qname))
 }
 
+// archiveAllPendingCmd is a Lua script that moves all pending tasks from
+// the given queue to archived state.
+//
+// Input:
 // KEYS[1] -> asynq:{<qname>}:pending
 // KEYS[2] -> asynq:{<qname>}:archived
 // ARGV[1] -> current timestamp
 // ARGV[2] -> cutoff timestamp (e.g., 90 days ago)
 // ARGV[3] -> max number of tasks in archive (e.g., 100)
+// ARGV[4] -> task key prefix (asynq:{<qname>}:t:)
+//
+// Output:
+// integer: Number of tasks archiveda
 var archiveAllPendingCmd = redis.NewScript(`
 local ids = redis.call("LRANGE", KEYS[1], 0, -1)
 for _, id in ipairs(ids) do
 	redis.call("ZADD", KEYS[2], ARGV[1], id)
-	redis.call("ZREMRANGEBYSCORE", KEYS[2], "-inf", ARGV[2])
-	redis.call("ZREMRANGEBYRANK", KEYS[2], 0, -ARGV[3])
+	redis.call("HSET", ARGV[4] .. id, "state", "archived")
 end
+redis.call("ZREMRANGEBYSCORE", KEYS[2], "-inf", ARGV[2])
+redis.call("ZREMRANGEBYRANK", KEYS[2], 0, -ARGV[3])
 redis.call("DEL", KEYS[1])
 return table.getn(ids)`)
 
 // ArchiveAllPendingTasks archives all pending tasks from the given queue and
 // returns the number of tasks moved.
 func (r *RDB) ArchiveAllPendingTasks(qname string) (int64, error) {
+	var op errors.Op = "rdb.ArchiveAllPendingTasks"
 	keys := []string{base.PendingKey(qname), base.ArchivedKey(qname)}
 	now := time.Now()
 	argv := []interface{}{
 		now.Unix(),
 		now.AddDate(0, 0, -archivedExpirationInDays).Unix(),
 		maxArchiveSize,
+		base.TaskKeyPrefix(qname),
 	}
 	res, err := archiveAllPendingCmd.Run(r.client, keys, argv...).Result()
 	if err != nil {
-		return 0, err
+		return 0, errors.E(op, errors.Internal, err)
 	}
 	n, ok := res.(int64)
 	if !ok {
-		return 0, fmt.Errorf("command error: unexpected return value %v", res)
+		return 0, errors.E(op, errors.Internal, fmt.Sprintf("unexpected return value from script %v", res))
 	}
 	return n, nil
 }