diff --git a/asynq_test.go b/asynq_test.go
new file mode 100644
index 0000000..2ef8a20
--- /dev/null
+++ b/asynq_test.go
@@ -0,0 +1,97 @@
+package asynq
+
+import (
+	"encoding/json"
+	"math/rand"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/uuid"
+)
+
+// This file defines test helper functions used by
+// other test files.
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+var sortMsgOpt = cmp.Transformer("SortMsg", func(in []*taskMessage) []*taskMessage {
+	out := append([]*taskMessage(nil), in...) // Copy input to avoid mutating it
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].ID.String() < out[j].ID.String()
+	})
+	return out
+})
+
+var sortTaskOpt = cmp.Transformer("SortMsg", func(in []*Task) []*Task {
+	out := append([]*Task(nil), in...) // Copy input to avoid mutating it
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].Type < out[j].Type
+	})
+	return out
+})
+
+// setup connects to a redis database and flush all keys
+// before returning an instance of rdb.
+func setup(t *testing.T) *rdb {
+	t.Helper()
+	r := newRDB(&RedisOpt{
+		Addr: "localhost:6379",
+		DB:   15, // use database 15 to separate from other applications
+	})
+	// Start each test with a clean slate.
+	if err := r.client.FlushDB().Err(); err != nil {
+		panic(err)
+	}
+	return r
+}
+
+func randomTask(taskType, qname string, payload map[string]interface{}) *taskMessage {
+	return &taskMessage{
+		ID:      uuid.New(),
+		Type:    taskType,
+		Queue:   qname,
+		Retry:   rand.Intn(100),
+		Payload: make(map[string]interface{}),
+	}
+}
+
+func mustMarshal(t *testing.T, task *taskMessage) string {
+	t.Helper()
+	data, err := json.Marshal(task)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(data)
+}
+
+func mustUnmarshal(t *testing.T, data string) *taskMessage {
+	t.Helper()
+	var task taskMessage
+	err := json.Unmarshal([]byte(data), &task)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &task
+}
+
+func mustMarshalSlice(t *testing.T, tasks []*taskMessage) []string {
+	t.Helper()
+	var data []string
+	for _, task := range tasks {
+		data = append(data, mustMarshal(t, task))
+	}
+	return data
+}
+
+func mustUnmarshalSlice(t *testing.T, data []string) []*taskMessage {
+	t.Helper()
+	var tasks []*taskMessage
+	for _, s := range data {
+		tasks = append(tasks, mustUnmarshal(t, s))
+	}
+	return tasks
+}
diff --git a/rdb_test.go b/rdb_test.go
index 17573a8..a246d6a 100644
--- a/rdb_test.go
+++ b/rdb_test.go
@@ -1,100 +1,14 @@
 package asynq
 
 import (
-	"encoding/json"
 	"fmt"
-	"math/rand"
-	"sort"
 	"testing"
 	"time"
 
 	"github.com/go-redis/redis/v7"
 	"github.com/google/go-cmp/cmp"
-	"github.com/google/uuid"
 )
 
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
-
-var sortMsgOpt = cmp.Transformer("SortMsg", func(in []*taskMessage) []*taskMessage {
-	out := append([]*taskMessage(nil), in...) // Copy input to avoid mutating it
-	sort.Slice(out, func(i, j int) bool {
-		return out[i].ID.String() < out[j].ID.String()
-	})
-	return out
-})
-
-var sortTaskOpt = cmp.Transformer("SortMsg", func(in []*Task) []*Task {
-	out := append([]*Task(nil), in...) // Copy input to avoid mutating it
-	sort.Slice(out, func(i, j int) bool {
-		return out[i].Type < out[j].Type
-	})
-	return out
-})
-
-// setup connects to a redis database and flush all keys
-// before returning an instance of rdb.
-func setup(t *testing.T) *rdb {
-	t.Helper()
-	r := newRDB(&RedisOpt{
-		Addr: "localhost:6379",
-		DB:   15, // use database 15 to separate from other applications
-	})
-	// Start each test with a clean slate.
-	if err := r.client.FlushDB().Err(); err != nil {
-		panic(err)
-	}
-	return r
-}
-
-func randomTask(taskType, qname string, payload map[string]interface{}) *taskMessage {
-	return &taskMessage{
-		ID:      uuid.New(),
-		Type:    taskType,
-		Queue:   qname,
-		Retry:   rand.Intn(100),
-		Payload: make(map[string]interface{}),
-	}
-}
-
-func mustMarshal(t *testing.T, task *taskMessage) string {
-	t.Helper()
-	data, err := json.Marshal(task)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return string(data)
-}
-
-func mustUnmarshal(t *testing.T, data string) *taskMessage {
-	t.Helper()
-	var task taskMessage
-	err := json.Unmarshal([]byte(data), &task)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return &task
-}
-
-func mustMarshalSlice(t *testing.T, tasks []*taskMessage) []string {
-	t.Helper()
-	var data []string
-	for _, task := range tasks {
-		data = append(data, mustMarshal(t, task))
-	}
-	return data
-}
-
-func mustUnmarshalSlice(t *testing.T, data []string) []*taskMessage {
-	t.Helper()
-	var tasks []*taskMessage
-	for _, s := range data {
-		tasks = append(tasks, mustUnmarshal(t, s))
-	}
-	return tasks
-}
-
 func TestEnqueue(t *testing.T) {
 	r := setup(t)
 	tests := []struct {