diff --git a/integration/cluster.go b/integration/cluster.go
index bc6881126..79e3f6d44 100644
--- a/integration/cluster.go
+++ b/integration/cluster.go
@@ -188,7 +188,7 @@ func (c *cluster) fillClusterForMembers() error {
 	return nil
 }
 
-func newCluster(t *testing.T, cfg *ClusterConfig) *cluster {
+func newCluster(t testing.TB, cfg *ClusterConfig) *cluster {
 	c := &cluster{cfg: cfg}
 	ms := make([]*member, cfg.Size)
 	for i := 0; i < cfg.Size; i++ {
@@ -204,16 +204,16 @@ func newCluster(t *testing.T, cfg *ClusterConfig) *cluster {
 
 // NewCluster returns an unlaunched cluster of the given size which has been
 // set to use static bootstrap.
-func NewCluster(t *testing.T, size int) *cluster {
+func NewCluster(t testing.TB, size int) *cluster {
 	return newCluster(t, &ClusterConfig{Size: size})
 }
 
 // NewClusterByConfig returns an unlaunched cluster defined by a cluster configuration
-func NewClusterByConfig(t *testing.T, cfg *ClusterConfig) *cluster {
+func NewClusterByConfig(t testing.TB, cfg *ClusterConfig) *cluster {
 	return newCluster(t, cfg)
 }
 
-func (c *cluster) Launch(t *testing.T) {
+func (c *cluster) Launch(t testing.TB) {
 	errc := make(chan error)
 	for _, m := range c.Members {
 		// Members are launched in separate goroutines because if they boot
@@ -274,7 +274,7 @@ func (c *cluster) HTTPMembers() []client.Member {
 	return ms
 }
 
-func (c *cluster) mustNewMember(t *testing.T) *member {
+func (c *cluster) mustNewMember(t testing.TB) *member {
 	m := mustNewMember(t,
 		memberConfig{
 			name:                     c.name(rand.Int()),
@@ -303,7 +303,7 @@ func (c *cluster) mustNewMember(t *testing.T) *member {
 	return m
 }
 
-func (c *cluster) addMember(t *testing.T) {
+func (c *cluster) addMember(t testing.TB) {
 	m := c.mustNewMember(t)
 
 	scheme := schemeFromTLSInfo(c.cfg.PeerTLS)
@@ -335,7 +335,7 @@ func (c *cluster) addMember(t *testing.T) {
 	c.waitMembersMatch(t, c.HTTPMembers())
 }
 
-func (c *cluster) addMemberByURL(t *testing.T, clientURL, peerURL string) error {
+func (c *cluster) addMemberByURL(t testing.TB, clientURL, peerURL string) error {
 	cc := MustNewHTTPClient(t, []string{clientURL}, c.cfg.ClientTLS)
 	ma := client.NewMembersAPI(cc)
 	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
@@ -351,17 +351,17 @@ func (c *cluster) addMemberByURL(t *testing.T, clientURL, peerURL string) error
 	return nil
 }
 
-func (c *cluster) AddMember(t *testing.T) {
+func (c *cluster) AddMember(t testing.TB) {
 	c.addMember(t)
 }
 
-func (c *cluster) RemoveMember(t *testing.T, id uint64) {
+func (c *cluster) RemoveMember(t testing.TB, id uint64) {
 	if err := c.removeMember(t, id); err != nil {
 		t.Fatal(err)
 	}
 }
 
-func (c *cluster) removeMember(t *testing.T, id uint64) error {
+func (c *cluster) removeMember(t testing.TB, id uint64) error {
 	// send remove request to the cluster
 	cc := MustNewHTTPClient(t, c.URLs(), c.cfg.ClientTLS)
 	ma := client.NewMembersAPI(cc)
@@ -392,7 +392,7 @@ func (c *cluster) removeMember(t *testing.T, id uint64) error {
 	return nil
 }
 
-func (c *cluster) Terminate(t *testing.T) {
+func (c *cluster) Terminate(t testing.TB) {
 	var wg sync.WaitGroup
 	wg.Add(len(c.Members))
 	for _, m := range c.Members {
@@ -404,7 +404,7 @@ func (c *cluster) Terminate(t *testing.T) {
 	wg.Wait()
 }
 
-func (c *cluster) waitMembersMatch(t *testing.T, membs []client.Member) {
+func (c *cluster) waitMembersMatch(t testing.TB, membs []client.Member) {
 	for _, u := range c.URLs() {
 		cc := MustNewHTTPClient(t, []string{u}, c.cfg.ClientTLS)
 		ma := client.NewMembersAPI(cc)
@@ -420,10 +420,10 @@ func (c *cluster) waitMembersMatch(t *testing.T, membs []client.Member) {
 	}
 }
 
-func (c *cluster) WaitLeader(t *testing.T) int { return c.waitLeader(t, c.Members) }
+func (c *cluster) WaitLeader(t testing.TB) int { return c.waitLeader(t, c.Members) }
 
 // waitLeader waits until given members agree on the same leader.
-func (c *cluster) waitLeader(t *testing.T, membs []*member) int {
+func (c *cluster) waitLeader(t testing.TB, membs []*member) int {
 	possibleLead := make(map[uint64]bool)
 	var lead uint64
 	for _, m := range membs {
@@ -516,14 +516,14 @@ func isMembersEqual(membs []client.Member, wmembs []client.Member) bool {
 	return reflect.DeepEqual(membs, wmembs)
 }
 
-func newLocalListener(t *testing.T) net.Listener {
+func newLocalListener(t testing.TB) net.Listener {
 	c := atomic.AddInt64(&localListenCount, 1)
 	// Go 1.8+ allows only numbers in port
 	addr := fmt.Sprintf("127.0.0.1:%05d%05d", c+basePort, os.Getpid())
 	return NewListenerWithAddr(t, addr)
 }
 
-func NewListenerWithAddr(t *testing.T, addr string) net.Listener {
+func NewListenerWithAddr(t testing.TB, addr string) net.Listener {
 	l, err := transport.NewUnixListener(addr)
 	if err != nil {
 		t.Fatal(err)
@@ -583,7 +583,7 @@ type memberConfig struct {
 
 // mustNewMember return an inited member with the given name. If peerTLS is
 // set, it will use https scheme to communicate between peers.
-func mustNewMember(t *testing.T, mcfg memberConfig) *member {
+func mustNewMember(t testing.TB, mcfg memberConfig) *member {
 	var err error
 	m := &member{}
 
@@ -759,7 +759,7 @@ func NewClientV3(m *member) (*clientv3.Client, error) {
 
 // Clone returns a member with the same server configuration. The returned
 // member will not set PeerListeners and ClientListeners.
-func (m *member) Clone(t *testing.T) *member {
+func (m *member) Clone(t testing.TB) *member {
 	mm := &member{}
 	mm.ServerConfig = m.ServerConfig
 
@@ -959,14 +959,14 @@ func (m *member) Launch() error {
 	return nil
 }
 
-func (m *member) WaitOK(t *testing.T) {
+func (m *member) WaitOK(t testing.TB) {
 	m.WaitStarted(t)
 	for m.s.Leader() == 0 {
 		time.Sleep(tickDuration)
 	}
 }
 
-func (m *member) WaitStarted(t *testing.T) {
+func (m *member) WaitStarted(t testing.TB) {
 	cc := MustNewHTTPClient(t, []string{m.URL()}, m.ClientTLSInfo)
 	kapi := client.NewKeysAPI(cc)
 	for {
@@ -981,7 +981,7 @@ func (m *member) WaitStarted(t *testing.T) {
 	}
 }
 
-func WaitClientV3(t *testing.T, kv clientv3.KV) {
+func WaitClientV3(t testing.TB, kv clientv3.KV) {
 	timeout := time.Now().Add(requestTimeout)
 	var err error
 	for time.Now().Before(timeout) {
@@ -1035,7 +1035,7 @@ func (m *member) Close() {
 }
 
 // Stop stops the member, but the data dir of the member is preserved.
-func (m *member) Stop(t *testing.T) {
+func (m *member) Stop(t testing.TB) {
 	lg.Info(
 		"stopping a member",
 		zap.String("name", m.Name),
@@ -1069,7 +1069,7 @@ func (m *member) StopNotify() <-chan struct{} {
 }
 
 // Restart starts the member using the preserved data dir.
-func (m *member) Restart(t *testing.T) error {
+func (m *member) Restart(t testing.TB) error {
 	lg.Info(
 		"restarting a member",
 		zap.String("name", m.Name),
@@ -1107,7 +1107,7 @@ func (m *member) Restart(t *testing.T) error {
 }
 
 // Terminate stops the member and removes the data dir.
-func (m *member) Terminate(t *testing.T) {
+func (m *member) Terminate(t testing.TB) {
 	lg.Info(
 		"terminating a member",
 		zap.String("name", m.Name),
@@ -1157,7 +1157,7 @@ func (m *member) Metric(metricName string) (string, error) {
 }
 
 // InjectPartition drops connections from m to others, vice versa.
-func (m *member) InjectPartition(t *testing.T, others ...*member) {
+func (m *member) InjectPartition(t testing.TB, others ...*member) {
 	for _, other := range others {
 		m.s.CutPeer(other.s.ID())
 		other.s.CutPeer(m.s.ID())
@@ -1165,14 +1165,14 @@ func (m *member) InjectPartition(t *testing.T, others ...*member) {
 }
 
 // RecoverPartition recovers connections from m to others, vice versa.
-func (m *member) RecoverPartition(t *testing.T, others ...*member) {
+func (m *member) RecoverPartition(t testing.TB, others ...*member) {
 	for _, other := range others {
 		m.s.MendPeer(other.s.ID())
 		other.s.MendPeer(m.s.ID())
 	}
 }
 
-func MustNewHTTPClient(t *testing.T, eps []string, tls *transport.TLSInfo) client.Client {
+func MustNewHTTPClient(t testing.TB, eps []string, tls *transport.TLSInfo) client.Client {
 	cfgtls := transport.TLSInfo{}
 	if tls != nil {
 		cfgtls = *tls
@@ -1185,7 +1185,7 @@ func MustNewHTTPClient(t *testing.T, eps []string, tls *transport.TLSInfo) clien
 	return c
 }
 
-func mustNewTransport(t *testing.T, tlsInfo transport.TLSInfo) *http.Transport {
+func mustNewTransport(t testing.TB, tlsInfo transport.TLSInfo) *http.Transport {
 	// tick in integration test is short, so 1s dial timeout could play well.
 	tr, err := transport.NewTimeoutTransport(tlsInfo, time.Second, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
 	if err != nil {
@@ -1211,7 +1211,7 @@ type ClusterV3 struct {
 
 // NewClusterV3 returns a launched cluster with a grpc client connection
 // for each cluster member.
-func NewClusterV3(t *testing.T, cfg *ClusterConfig) *ClusterV3 {
+func NewClusterV3(t testing.TB, cfg *ClusterConfig) *ClusterV3 {
 	cfg.UseGRPC = true
 	if os.Getenv("CLIENT_DEBUG") != "" {
 		clientv3.SetLogger(grpclog.NewLoggerV2WithVerbosity(os.Stderr, os.Stderr, os.Stderr, 4))
@@ -1240,7 +1240,7 @@ func (c *ClusterV3) TakeClient(idx int) {
 	c.mu.Unlock()
 }
 
-func (c *ClusterV3) Terminate(t *testing.T) {
+func (c *ClusterV3) Terminate(t testing.TB) {
 	c.mu.Lock()
 	for _, client := range c.clients {
 		if client == nil {