diff --git a/gossip/comm/comm_test.go b/gossip/comm/comm_test.go
index 8f33b845f4c..96cdc0e9776 100644
--- a/gossip/comm/comm_test.go
+++ b/gossip/comm/comm_test.go
@@ -70,6 +70,7 @@ func newCommInstance(port int, sec SecurityProvider) (Comm, error) {
 }
 
 func TestHandshake(t *testing.T) {
+	t.Parallel()
 	comm1, _ := newCommInstance(9611, naiveSec)
 	defer comm1.Stop()
 
@@ -246,8 +247,8 @@ func TestBlackListPKIid(t *testing.T) {
 
 func TestParallelSend(t *testing.T) {
 	t.Parallel()
-	comm1, _ := newCommInstance(5611, naiveSec)
-	comm2, _ := newCommInstance(5612, naiveSec)
+	comm1, _ := newCommInstance(5411, naiveSec)
+	comm2, _ := newCommInstance(5412, naiveSec)
 	defer comm1.Stop()
 	defer comm2.Stop()
 
@@ -260,7 +261,7 @@ func TestParallelSend(t *testing.T) {
 			emptyMsg := createGossipMsg()
 			go func() {
 				defer wg.Done()
-				comm1.Send(emptyMsg, remotePeer(5612))
+				comm1.Send(emptyMsg, remotePeer(5412))
 			}()
 		}
 		wg.Wait()
diff --git a/gossip/comm/crypto_test.go b/gossip/comm/crypto_test.go
index d5b96603d7a..ecf31ad9f97 100644
--- a/gossip/comm/crypto_test.go
+++ b/gossip/comm/crypto_test.go
@@ -78,7 +78,7 @@ func TestCertificateGeneration(t *testing.T) {
 		return
 	}
 	s := grpc.NewServer(grpc.Creds(creds))
-	ll, err = net.Listen("tcp", fmt.Sprintf("%s:%d", "", 5611))
+	ll, err = net.Listen("tcp", fmt.Sprintf("%s:%d", "", 5511))
 	assert.NoError(t, err, "%v", err)
 	if err != nil {
 		return
@@ -98,7 +98,7 @@ func TestCertificateGeneration(t *testing.T) {
 	if err != nil {
 		return
 	}
-	conn, err := grpc.Dial("localhost:5611", grpc.WithTransportCredentials(&authCreds{tlsCreds: ta}), grpc.WithBlock(), grpc.WithTimeout(time.Second))
+	conn, err := grpc.Dial("localhost:5511", grpc.WithTransportCredentials(&authCreds{tlsCreds: ta}), grpc.WithBlock(), grpc.WithTimeout(time.Second))
 	assert.NoError(t, err, "%v", err)
 	if err != nil {
 		return
diff --git a/gossip/discovery/discovery_test.go b/gossip/discovery/discovery_test.go
index 428f786652c..ff96bae2f11 100644
--- a/gossip/discovery/discovery_test.go
+++ b/gossip/discovery/discovery_test.go
@@ -259,6 +259,7 @@ func bootPeer(port int) string {
 }
 
 func TestUpdate(t *testing.T) {
+	t.Parallel()
 	nodeNum := 5
 	bootPeers := []string{bootPeer(6611), bootPeer(6612)}
 	instances := []*gossipInstance{}
@@ -308,6 +309,7 @@ func TestUpdate(t *testing.T) {
 }
 
 func TestInitiateSync(t *testing.T) {
+	t.Parallel()
 	nodeNum := 10
 	bootPeers := []string{bootPeer(3611), bootPeer(3612)}
 	instances := []*gossipInstance{}
@@ -334,6 +336,7 @@ func TestInitiateSync(t *testing.T) {
 }
 
 func TestExpiration(t *testing.T) {
+	t.Parallel()
 	nodeNum := 5
 	bootPeers := []string{bootPeer(2611), bootPeer(2612)}
 	instances := []*gossipInstance{}
@@ -373,19 +376,20 @@ func TestExpiration(t *testing.T) {
 }
 
 func TestGetFullMembership(t *testing.T) {
+	t.Parallel()
 	nodeNum := 15
-	bootPeers := []string{bootPeer(5611), bootPeer(5612)}
+	bootPeers := []string{bootPeer(5511), bootPeer(5512)}
 	instances := []*gossipInstance{}
 
-	inst := createDiscoveryInstance(5611, "d1", bootPeers)
+	inst := createDiscoveryInstance(5511, "d1", bootPeers)
 	instances = append(instances, inst)
 
-	inst = createDiscoveryInstance(5612, "d2", bootPeers)
+	inst = createDiscoveryInstance(5512, "d2", bootPeers)
 	instances = append(instances, inst)
 
 	for i := 3; i <= nodeNum; i++ {
 		id := fmt.Sprintf("d%d", i)
-		inst = createDiscoveryInstance(5610+i, id, bootPeers)
+		inst = createDiscoveryInstance(5510+i, id, bootPeers)
 		instances = append(instances, inst)
 	}
 
@@ -394,6 +398,7 @@ func TestGetFullMembership(t *testing.T) {
 }
 
 func TestGossipDiscoveryStopping(t *testing.T) {
+	t.Parallel()
 	inst := createDiscoveryInstance(9611, "d1", []string{bootPeer(9611)})
 	time.Sleep(time.Second)
 	waitUntilOrFailBlocking(t, inst.Stop)
@@ -401,6 +406,7 @@ func TestGossipDiscoveryStopping(t *testing.T) {
 }
 
 func TestConvergence(t *testing.T) {
+	t.Parallel()
 	// scenario:
 	// {boot peer: [peer list]}
 	// {d1: d2, d3, d4}