diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index 8086eb795..12528c7e7 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -104,7 +104,7 @@
 		},
 		{
 			"ImportPath": "github.com/xiang90/probing",
-			"Rev": "11caf1c32ca4055f97e55541e92a75966635981d"
+			"Rev": "6a0cc1ae81b4cc11db5e491e030e4b98fba79c19"
 		},
 		{
 			"ImportPath": "golang.org/x/crypto/bcrypt",
diff --git a/Godeps/_workspace/src/github.com/xiang90/probing/prober.go b/Godeps/_workspace/src/github.com/xiang90/probing/prober.go
index d34fa2b22..9f04f8602 100644
--- a/Godeps/_workspace/src/github.com/xiang90/probing/prober.go
+++ b/Godeps/_workspace/src/github.com/xiang90/probing/prober.go
@@ -24,10 +24,17 @@ type Prober interface {
 type prober struct {
 	mu      sync.Mutex
 	targets map[string]*status
+	tr      http.RoundTripper
 }
 
-func NewProber() Prober {
-	return &prober{targets: make(map[string]*status)}
+func NewProber(tr http.RoundTripper) Prober {
+	p := &prober{targets: make(map[string]*status)}
+	if tr == nil {
+		p.tr = http.DefaultTransport
+	} else {
+		p.tr = tr
+	}
+	return p
 }
 
 func (p *prober) AddHTTP(id string, probingInterval time.Duration, endpoints []string) error {
@@ -48,7 +55,11 @@ func (p *prober) AddHTTP(id string, probingInterval time.Duration, endpoints []s
 			select {
 			case <-ticker.C:
 				start := time.Now()
-				resp, err := http.Get(endpoints[pinned])
+				req, err := http.NewRequest("GET", endpoints[pinned], nil)
+				if err != nil {
+					panic(err)
+				}
+				resp, err := p.tr.RoundTrip(req)
 				if err != nil {
 					s.recordFailure()
 					pinned = (pinned + 1) % len(endpoints)
diff --git a/Godeps/_workspace/src/github.com/xiang90/probing/prober_test.go b/Godeps/_workspace/src/github.com/xiang90/probing/prober_test.go
index d80bbcaa7..147f6bfa6 100644
--- a/Godeps/_workspace/src/github.com/xiang90/probing/prober_test.go
+++ b/Godeps/_workspace/src/github.com/xiang90/probing/prober_test.go
@@ -13,7 +13,7 @@ var (
 func TestProbe(t *testing.T) {
 	s := httptest.NewServer(NewHandler())
 
-	p := NewProber()
+	p := NewProber(nil)
 	p.AddHTTP(testID, time.Millisecond, []string{s.URL})
 	defer p.Remove(testID)
 
@@ -48,7 +48,7 @@ func TestProbeReset(t *testing.T) {
 	s := httptest.NewServer(NewHandler())
 	defer s.Close()
 
-	p := NewProber()
+	p := NewProber(nil)
 	p.AddHTTP(testID, time.Millisecond, []string{s.URL})
 	defer p.Remove(testID)
 
@@ -79,7 +79,7 @@ func TestProbeRemove(t *testing.T) {
 	s := httptest.NewServer(NewHandler())
 	defer s.Close()
 
-	p := NewProber()
+	p := NewProber(nil)
 	p.AddHTTP(testID, time.Millisecond, []string{s.URL})
 
 	p.Remove(testID)
diff --git a/rafthttp/transport.go b/rafthttp/transport.go
index e856ed2ce..b70f4018b 100644
--- a/rafthttp/transport.go
+++ b/rafthttp/transport.go
@@ -100,7 +100,7 @@ func NewTransporter(rt http.RoundTripper, id, cid types.ID, r Raft, errorc chan
 		remotes:      make(map[types.ID]*remote),
 		peers:        make(map[types.ID]Peer),
 
-		prober: probing.NewProber(),
+		prober: probing.NewProber(rt),
 		errorc: errorc,
 	}
 }
diff --git a/rafthttp/transport_test.go b/rafthttp/transport_test.go
index d0492109a..4a8dc4cf7 100644
--- a/rafthttp/transport_test.go
+++ b/rafthttp/transport_test.go
@@ -74,7 +74,7 @@ func TestTransportAdd(t *testing.T) {
 		leaderStats:  ls,
 		term:         term,
 		peers:        make(map[types.ID]Peer),
-		prober:       probing.NewProber(),
+		prober:       probing.NewProber(nil),
 	}
 	tr.AddPeer(1, []string{"http://localhost:2380"})
 
@@ -106,7 +106,7 @@ func TestTransportRemove(t *testing.T) {
 		roundTripper: &roundTripperRecorder{},
 		leaderStats:  stats.NewLeaderStats(""),
 		peers:        make(map[types.ID]Peer),
-		prober:       probing.NewProber(),
+		prober:       probing.NewProber(nil),
 	}
 	tr.AddPeer(1, []string{"http://localhost:2380"})
 	tr.RemovePeer(types.ID(1))
@@ -121,7 +121,7 @@ func TestTransportUpdate(t *testing.T) {
 	peer := newFakePeer()
 	tr := &transport{
 		peers:  map[types.ID]Peer{types.ID(1): peer},
-		prober: probing.NewProber(),
+		prober: probing.NewProber(nil),
 	}
 	u := "http://localhost:2380"
 	tr.UpdatePeer(types.ID(1), []string{u})
@@ -137,7 +137,7 @@ func TestTransportErrorc(t *testing.T) {
 		roundTripper: newRespRoundTripper(http.StatusForbidden, nil),
 		leaderStats:  stats.NewLeaderStats(""),
 		peers:        make(map[types.ID]Peer),
-		prober:       probing.NewProber(),
+		prober:       probing.NewProber(nil),
 		errorc:       errorc,
 	}
 	tr.AddPeer(1, []string{"http://localhost:2380"})