diff --git a/internal/rdb/rdb.go b/internal/rdb/rdb.go
index d032043..c6d1501 100644
--- a/internal/rdb/rdb.go
+++ b/internal/rdb/rdb.go
@@ -333,7 +333,11 @@ func (r *RDB) Requeue(msg *base.TaskMessage) error {
 // ARGV[4] -> task timeout in seconds (0 if not timeout)
 // ARGV[5] -> task deadline in unix time (0 if no deadline)
 var scheduleCmd = redis.NewScript(`
-redis.call("HSET", KEYS[1], "msg", ARGV[1], "timeout", ARGV[4], "deadline", ARGV[5])
+redis.call("HSET", KEYS[1],
+           "msg", ARGV[1],
+           "state", "scheduled",
+           "timeout", ARGV[4],
+           "deadline", ARGV[5])
 redis.call("ZADD", KEYS[2], ARGV[2], ARGV[3])
 return 1
 `)
diff --git a/internal/rdb/rdb_test.go b/internal/rdb/rdb_test.go
index 0ca1397..38eb752 100644
--- a/internal/rdb/rdb_test.go
+++ b/internal/rdb/rdb_test.go
@@ -86,8 +86,8 @@ func TestEnqueue(t *testing.T) {
 		// Check Pending list has task ID.
 		pendingKey := base.PendingKey(tc.msg.Queue)
 		pendingIDs := r.client.LRange(pendingKey, 0, -1).Val()
-		if len(pendingIDs) != 1 {
-			t.Errorf("Redis LIST %q contains %d IDs, want 1", pendingKey, len(pendingIDs))
+		if n := len(pendingIDs); n != 1 {
+			t.Errorf("Redis LIST %q contains %d IDs, want 1", pendingKey, n)
 			continue
 		}
 		if pendingIDs[0] != tc.msg.ID.String() {
@@ -831,24 +831,55 @@ func TestSchedule(t *testing.T) {
 	for _, tc := range tests {
 		h.FlushDB(t, r.client) // clean up db before each test case
 
-		desc := fmt.Sprintf("(*RDB).Schedule(%v, %v)", tc.msg, tc.processAt)
 		err := r.Schedule(tc.msg, tc.processAt)
 		if err != nil {
-			t.Errorf("%s = %v, want nil", desc, err)
+			t.Errorf("(*RDB).Schedule(%v, %v) = %v, want nil",
+				tc.msg, tc.processAt, err)
 			continue
 		}
 
-		gotScheduled := h.GetScheduledEntries(t, r.client, tc.msg.Queue)
-		if len(gotScheduled) != 1 {
-			t.Errorf("%s inserted %d items to %q, want 1 items inserted",
-				desc, len(gotScheduled), base.ScheduledKey(tc.msg.Queue))
+		// Check Scheduled zset has task ID.
+		scheduledKey := base.ScheduledKey(tc.msg.Queue)
+		zs := r.client.ZRangeWithScores(scheduledKey, 0, -1).Val()
+		if n := len(zs); n != 1 {
+			t.Errorf("Redis ZSET %q contains %d elements, want 1",
+				scheduledKey, n)
 			continue
 		}
-		if int64(gotScheduled[0].Score) != tc.processAt.Unix() {
-			t.Errorf("%s inserted an item with score %d, want %d",
-				desc, int64(gotScheduled[0].Score), tc.processAt.Unix())
+		if got := zs[0].Member.(string); got != tc.msg.ID.String() {
+			t.Errorf("Redis ZSET %q member: got %v, want %v",
+				scheduledKey, got, tc.msg.ID.String())
 			continue
 		}
+		if got := int64(zs[0].Score); got != tc.processAt.Unix() {
+			t.Errorf("Redis ZSET %q score: got %d, want %d",
+				scheduledKey, got, tc.processAt.Unix())
+			continue
+		}
+
+		// Check the values under the task key.
+		taskKey := base.TaskKey(tc.msg.Queue, tc.msg.ID.String())
+		encoded := r.client.HGet(taskKey, "msg").Val() // "msg" field
+		decoded := h.MustUnmarshal(t, encoded)
+		if diff := cmp.Diff(tc.msg, decoded); diff != "" {
+			t.Errorf("persisted message was %v, want %v; (-want, +got)\n%s",
+				decoded, tc.msg, diff)
+		}
+		state := r.client.HGet(taskKey, "state").Val() // "state" field
+		if want := "scheduled"; state != want {
+			t.Errorf("state field under task-key is set to %q, want %q",
+				state, want)
+		}
+		timeout := r.client.HGet(taskKey, "timeout").Val() // "timeout" field
+		if want := strconv.Itoa(int(tc.msg.Timeout)); timeout != want {
+			t.Errorf("timeout field under task-key is set to %v, want %v", timeout, want)
+		}
+		deadline := r.client.HGet(taskKey, "deadline").Val() // "deadline" field
+		if want := strconv.Itoa(int(tc.msg.Deadline)); deadline != want {
+			t.Errorf("deadline field under task-ke is set to %v, want %v", deadline, want)
+		}
+
+		// Check queue is in the AllQueues set.
 		if !r.client.SIsMember(base.AllQueues, tc.msg.Queue).Val() {
 			t.Errorf("%q is not a member of SET %q", tc.msg.Queue, base.AllQueues)
 		}