diff --git a/internal/asynqtest/asynqtest.go b/internal/asynqtest/asynqtest.go
index 935bc1f..061b6ef 100644
--- a/internal/asynqtest/asynqtest.go
+++ b/internal/asynqtest/asynqtest.go
@@ -323,43 +323,94 @@ func GetActiveMessages(tb testing.TB, r redis.UniversalClient, qname string) []*
 // GetScheduledMessages returns all scheduled task messages in the given queue.
 func GetScheduledMessages(tb testing.TB, r redis.UniversalClient, qname string) []*base.TaskMessage {
 	tb.Helper()
-	return getZSetMessages(tb, r, base.ScheduledKey(qname))
+	ids := r.ZRange(base.ScheduledKey(qname), 0, -1).Val()
+	var msgs []*base.TaskMessage
+	for _, id := range ids {
+		msg := r.Get(base.TaskKey(qname, id)).Val()
+		msgs = append(msgs, MustUnmarshal(tb, msg))
+	}
+	return msgs
 }
 
 // GetRetryMessages returns all retry messages in the given queue.
 func GetRetryMessages(tb testing.TB, r redis.UniversalClient, qname string) []*base.TaskMessage {
 	tb.Helper()
-	return getZSetMessages(tb, r, base.RetryKey(qname))
+	ids := r.ZRange(base.RetryKey(qname), 0, -1).Val()
+	var msgs []*base.TaskMessage
+	for _, id := range ids {
+		msg := r.Get(base.TaskKey(qname, id)).Val()
+		msgs = append(msgs, MustUnmarshal(tb, msg))
+	}
+	return msgs
 }
 
 // GetArchivedMessages returns all archived messages in the given queue.
 func GetArchivedMessages(tb testing.TB, r redis.UniversalClient, qname string) []*base.TaskMessage {
 	tb.Helper()
-	return getZSetMessages(tb, r, base.ArchivedKey(qname))
+	ids := r.ZRange(base.ArchivedKey(qname), 0, -1).Val()
+	var msgs []*base.TaskMessage
+	for _, id := range ids {
+		msg := r.Get(base.TaskKey(qname, id)).Val()
+		msgs = append(msgs, MustUnmarshal(tb, msg))
+	}
+	return msgs
 }
 
 // GetScheduledEntries returns all scheduled messages and its score in the given queue.
 func GetScheduledEntries(tb testing.TB, r redis.UniversalClient, qname string) []base.Z {
 	tb.Helper()
-	return getZSetEntries(tb, r, base.ScheduledKey(qname))
+	zs := r.ZRangeWithScores(base.ScheduledKey(qname), 0, -1).Val()
+	var res []base.Z
+	for _, z := range zs {
+		msg := r.Get(base.TaskKey(qname, z.Member.(string))).Val()
+		res = append(res, base.Z{Message: MustUnmarshal(tb, msg), Score: int64(z.Score)})
+	}
+	return res
 }
 
 // GetRetryEntries returns all retry messages and its score in the given queue.
 func GetRetryEntries(tb testing.TB, r redis.UniversalClient, qname string) []base.Z {
 	tb.Helper()
-	return getZSetEntries(tb, r, base.RetryKey(qname))
+	zs := r.ZRangeWithScores(base.RetryKey(qname), 0, -1).Val()
+	var res []base.Z
+	for _, z := range zs {
+		msg := r.Get(base.TaskKey(qname, z.Member.(string))).Val()
+		res = append(res, base.Z{
+			Message: MustUnmarshal(tb, msg),
+			Score:   int64(z.Score),
+		})
+	}
+	return res
 }
 
 // GetArchivedEntries returns all archived messages and its score in the given queue.
 func GetArchivedEntries(tb testing.TB, r redis.UniversalClient, qname string) []base.Z {
 	tb.Helper()
-	return getZSetEntries(tb, r, base.ArchivedKey(qname))
+	zs := r.ZRangeWithScores(base.ArchivedKey(qname), 0, -1).Val()
+	var res []base.Z
+	for _, z := range zs {
+		msg := r.Get(base.TaskKey(qname, z.Member.(string))).Val()
+		res = append(res, base.Z{
+			Message: MustUnmarshal(tb, msg),
+			Score:   int64(z.Score),
+		})
+	}
+	return res
 }
 
 // GetDeadlinesEntries returns all task messages and its score in the deadlines set for the given queue.
 func GetDeadlinesEntries(tb testing.TB, r redis.UniversalClient, qname string) []base.Z {
 	tb.Helper()
-	return getZSetEntries(tb, r, base.DeadlinesKey(qname))
+	zs := r.ZRangeWithScores(base.DeadlinesKey(qname), 0, -1).Val()
+	var res []base.Z
+	for _, z := range zs {
+		msg := r.Get(base.TaskKey(qname, z.Member.(string))).Val()
+		res = append(res, base.Z{
+			Message: MustUnmarshal(tb, msg),
+			Score:   int64(z.Score),
+		})
+	}
+	return res
 }
 
 func getListMessages(tb testing.TB, r redis.UniversalClient, list string) []*base.TaskMessage {
diff --git a/internal/rdb/rdb.go b/internal/rdb/rdb.go
index 5666be6..35d5ad3 100644
--- a/internal/rdb/rdb.go
+++ b/internal/rdb/rdb.go
@@ -288,7 +288,18 @@ func (r *RDB) Requeue(msg *base.TaskMessage) error {
 		encoded).Err()
 }
 
-// Schedule adds the task to the backlog queue to be processed in the future.
+// KEYS[1] -> asynq:{<qname>}:t:<task_id>
+// KEYS[2] -> asynq:{<qname>}:scheduled
+// ARGV[1] -> task message data
+// ARGV[2] -> process_at time in Unix time
+// ARGV[3] -> task ID
+var scheduleCmd = redis.NewScript(`
+redis.call("SET", KEYS[1], ARGV[1])
+redis.call("ZADD", KEYS[2], ARGV[2], ARGV[3])
+return 1
+`)
+
+// Schedule adds the task to the scheduled set to be processed in the future.
 func (r *RDB) Schedule(msg *base.TaskMessage, processAt time.Time) error {
 	encoded, err := base.EncodeMessage(msg)
 	if err != nil {
@@ -297,8 +308,9 @@ func (r *RDB) Schedule(msg *base.TaskMessage, processAt time.Time) error {
 	if err := r.client.SAdd(base.AllQueues, msg.Queue).Err(); err != nil {
 		return err
 	}
-	score := float64(processAt.Unix())
-	return r.client.ZAdd(base.ScheduledKey(msg.Queue), &redis.Z{Score: score, Member: encoded}).Err()
+	keys := []string{base.TaskKey(msg.Queue, msg.ID.String()), base.ScheduledKey(msg.Queue)}
+	args := []interface{}{encoded, processAt.Unix(), msg.ID.String()}
+	return scheduleCmd.Run(r.client, keys, args...).Err()
 }
 
 // KEYS[1] -> unique key
diff --git a/internal/rdb/rdb_test.go b/internal/rdb/rdb_test.go
index 40b2885..a24aebf 100644
--- a/internal/rdb/rdb_test.go
+++ b/internal/rdb/rdb_test.go
@@ -765,12 +765,12 @@ func TestRequeue(t *testing.T) {
 func TestSchedule(t *testing.T) {
 	r := setup(t)
 	defer r.Close()
-	t1 := h.NewTaskMessage("send_email", map[string]interface{}{"subject": "hello"})
+	msg := h.NewTaskMessage("send_email", map[string]interface{}{"subject": "hello"})
 	tests := []struct {
 		msg       *base.TaskMessage
 		processAt time.Time
 	}{
-		{t1, time.Now().Add(15 * time.Minute)},
+		{msg, time.Now().Add(15 * time.Minute)},
 	}
 
 	for _, tc := range tests {