diff --git a/periodic_task_manager_test.go b/periodic_task_manager_test.go
index 24d5e5b..b3c067a 100644
--- a/periodic_task_manager_test.go
+++ b/periodic_task_manager_test.go
@@ -32,6 +32,7 @@ func (p *FakeConfigProvider) GetConfigs() ([]*PeriodicTaskConfig, error) {
 }
 
 func TestNewPeriodicTaskManager(t *testing.T) {
+	redisConnOpt := getRedisConnOpt(t)
 	cfgs := []*PeriodicTaskConfig{
 		{Cronspec: "* * * * *", Task: NewTask("foo", nil)},
 		{Cronspec: "* * * * *", Task: NewTask("bar", nil)},
@@ -43,14 +44,14 @@ func TestNewPeriodicTaskManager(t *testing.T) {
 		{
 			desc: "with provider and redisConnOpt",
 			opts: PeriodicTaskManagerOpts{
-				RedisConnOpt:               RedisClientOpt{Addr: ":6379"},
+				RedisConnOpt:               redisConnOpt,
 				PeriodicTaskConfigProvider: &FakeConfigProvider{cfgs: cfgs},
 			},
 		},
 		{
 			desc: "with sync option",
 			opts: PeriodicTaskManagerOpts{
-				RedisConnOpt:               RedisClientOpt{Addr: ":6379"},
+				RedisConnOpt:               redisConnOpt,
 				PeriodicTaskConfigProvider: &FakeConfigProvider{cfgs: cfgs},
 				SyncInterval:               5 * time.Minute,
 			},
@@ -58,7 +59,7 @@ func TestNewPeriodicTaskManager(t *testing.T) {
 		{
 			desc: "with scheduler option",
 			opts: PeriodicTaskManagerOpts{
-				RedisConnOpt:               RedisClientOpt{Addr: ":6379"},
+				RedisConnOpt:               redisConnOpt,
 				PeriodicTaskConfigProvider: &FakeConfigProvider{cfgs: cfgs},
 				SyncInterval:               5 * time.Minute,
 				SchedulerOpts: &SchedulerOpts{
@@ -74,37 +75,33 @@ func TestNewPeriodicTaskManager(t *testing.T) {
 			t.Errorf("%s; NewPeriodicTaskManager returned error: %v", tc.desc, err)
 		}
 	}
-}
 
-func TestNewPeriodicTaskManagerError(t *testing.T) {
-	cfgs := []*PeriodicTaskConfig{
-		{Cronspec: "* * * * *", Task: NewTask("foo", nil)},
-		{Cronspec: "* * * * *", Task: NewTask("bar", nil)},
-	}
-	tests := []struct {
-		desc string
-		opts PeriodicTaskManagerOpts
-	}{
-		{
-			desc: "without provider",
-			opts: PeriodicTaskManagerOpts{
-				RedisConnOpt: RedisClientOpt{Addr: ":6379"},
+	t.Run("error", func(t *testing.T) {
+		tests := []struct {
+			desc string
+			opts PeriodicTaskManagerOpts
+		}{
+			{
+				desc: "without provider",
+				opts: PeriodicTaskManagerOpts{
+					RedisConnOpt: redisConnOpt,
+				},
 			},
-		},
-		{
-			desc: "without redisConOpt",
-			opts: PeriodicTaskManagerOpts{
-				PeriodicTaskConfigProvider: &FakeConfigProvider{cfgs: cfgs},
+			{
+				desc: "without redisConOpt",
+				opts: PeriodicTaskManagerOpts{
+					PeriodicTaskConfigProvider: &FakeConfigProvider{cfgs: cfgs},
+				},
 			},
-		},
-	}
-
-	for _, tc := range tests {
-		_, err := NewPeriodicTaskManager(tc.opts)
-		if err == nil {
-			t.Errorf("%s; NewPeriodicTaskManager did not return error", tc.desc)
 		}
-	}
+
+		for _, tc := range tests {
+			_, err := NewPeriodicTaskManager(tc.opts)
+			if err == nil {
+				t.Errorf("%s; NewPeriodicTaskManager did not return error", tc.desc)
+			}
+		}
+	})
 }
 
 func TestPeriodicTaskConfigHash(t *testing.T) {
diff --git a/scheduler_test.go b/scheduler_test.go
index a35f390..619a1b7 100644
--- a/scheduler_test.go
+++ b/scheduler_test.go
@@ -5,12 +5,12 @@
 package asynq
 
 import (
-	"github.com/redis/go-redis/v9"
 	"sync"
 	"testing"
 	"time"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/redis/go-redis/v9"
 
 	"github.com/hibiken/asynq/internal/base"
 	"github.com/hibiken/asynq/internal/testutil"
@@ -114,7 +114,7 @@ func TestSchedulerWhenRedisDown(t *testing.T) {
 
 	// Connect to non-existent redis instance to simulate a redis server being down.
 	scheduler := NewScheduler(
-		RedisClientOpt{Addr: ":9876"},
+		RedisClientOpt{Addr: ":9876"}, // no Redis listening to this port.
 		&SchedulerOpts{EnqueueErrorHandler: errorHandler},
 	)
 
diff --git a/server_test.go b/server_test.go
index 3d39e4a..967f519 100644
--- a/server_test.go
+++ b/server_test.go
@@ -85,7 +85,7 @@ func TestServerRun(t *testing.T) {
 	ignoreOpt := goleak.IgnoreTopFunction("github.com/redis/go-redis/v9/internal/pool.(*ConnPool).reaper")
 	defer goleak.VerifyNone(t, ignoreOpt)
 
-	srv := NewServer(RedisClientOpt{Addr: ":6379"}, Config{LogLevel: testLogLevel})
+	srv := NewServer(getRedisConnOpt(t), Config{LogLevel: testLogLevel})
 
 	done := make(chan struct{})
 	// Make sure server exits when receiving TERM signal.
@@ -110,7 +110,7 @@ func TestServerRun(t *testing.T) {
 }
 
 func TestServerErrServerClosed(t *testing.T) {
-	srv := NewServer(RedisClientOpt{Addr: ":6379"}, Config{LogLevel: testLogLevel})
+	srv := NewServer(getRedisConnOpt(t), Config{LogLevel: testLogLevel})
 	handler := NewServeMux()
 	if err := srv.Start(handler); err != nil {
 		t.Fatal(err)
@@ -123,7 +123,7 @@ func TestServerErrServerClosed(t *testing.T) {
 }
 
 func TestServerErrNilHandler(t *testing.T) {
-	srv := NewServer(RedisClientOpt{Addr: ":6379"}, Config{LogLevel: testLogLevel})
+	srv := NewServer(getRedisConnOpt(t), Config{LogLevel: testLogLevel})
 	err := srv.Start(nil)
 	if err == nil {
 		t.Error("Starting server with nil handler: (*Server).Start(nil) did not return error")
@@ -132,7 +132,7 @@ func TestServerErrNilHandler(t *testing.T) {
 }
 
 func TestServerErrServerRunning(t *testing.T) {
-	srv := NewServer(RedisClientOpt{Addr: ":6379"}, Config{LogLevel: testLogLevel})
+	srv := NewServer(getRedisConnOpt(t), Config{LogLevel: testLogLevel})
 	handler := NewServeMux()
 	if err := srv.Start(handler); err != nil {
 		t.Fatal(err)
@@ -153,7 +153,7 @@ func TestServerWithRedisDown(t *testing.T) {
 	}()
 	r := rdb.NewRDB(setup(t))
 	testBroker := testbroker.NewTestBroker(r)
-	srv := NewServer(RedisClientOpt{Addr: ":6379"}, Config{LogLevel: testLogLevel})
+	srv := NewServer(getRedisConnOpt(t), Config{LogLevel: testLogLevel})
 	srv.broker = testBroker
 	srv.forwarder.broker = testBroker
 	srv.heartbeater.broker = testBroker