diff --git a/testing/scenarios/feature_test.go b/testing/scenarios/feature_test.go
index 454b2a616..3ff80d7d2 100644
--- a/testing/scenarios/feature_test.go
+++ b/testing/scenarios/feature_test.go
@@ -2,6 +2,7 @@ package scenarios
 
 import (
 	"context"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -441,8 +442,8 @@ func TestBlackhole(t *testing.T) {
 	common.Must(err)
 	defer CloseAllServers(servers)
 
-	if err := testTCPConn(serverPort2, 1024, time.Second*5)(); err != nil {
-		t.Error(err)
+	if err := testTCPConn(serverPort2, 1024, time.Second*5)(); err != io.EOF {
+		t.Error("unexpected error: ", err)
 	}
 }
 
diff --git a/testing/scenarios/shadowsocks_test.go b/testing/scenarios/shadowsocks_test.go
index 1f2a3ae93..21fd94cf3 100644
--- a/testing/scenarios/shadowsocks_test.go
+++ b/testing/scenarios/shadowsocks_test.go
@@ -342,7 +342,7 @@ func TestShadowsocksChacha20TCP(t *testing.T) {
 
 	var errg errgroup.Group
 	for i := 0; i < 10; i++ {
-		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*20))
+		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*40))
 	}
 
 	if err := errg.Wait(); err != nil {
diff --git a/testing/scenarios/vmess_test.go b/testing/scenarios/vmess_test.go
index 9fe997780..413da2e8a 100644
--- a/testing/scenarios/vmess_test.go
+++ b/testing/scenarios/vmess_test.go
@@ -456,7 +456,7 @@ func TestVMessGCMUDP(t *testing.T) {
 
 	var errg errgroup.Group
 	for i := 0; i < 10; i++ {
-		errg.Go(testTCPConn(clientPort, 1024, time.Second*5))
+		errg.Go(testUDPConn(clientPort, 1024, time.Second*5))
 	}
 	if err := errg.Wait(); err != nil {
 		t.Error(err)