diff --git a/p2p/pex/pex_reactor_test.go b/p2p/pex/pex_reactor_test.go
index 68443e74b..fc40f6fa0 100644
--- a/p2p/pex/pex_reactor_test.go
+++ b/p2p/pex/pex_reactor_test.go
@@ -73,7 +73,7 @@ func TestPEXReactorRunning(t *testing.T) {
 
 	// create switches
 	for i := 0; i < N; i++ {
-		switches[i] = p2p.MakeSwitch(config, i, "127.0.0.2", "123.123.123", func(i int, sw *p2p.Switch) *p2p.Switch {
+		switches[i] = p2p.MakeSwitch(config, i, "testing", "123.123.123", func(i int, sw *p2p.Switch) *p2p.Switch {
 			books[i] = NewAddrBook(filepath.Join(dir, fmt.Sprintf("addrbook%d.json", i)), false)
 			books[i].SetLogger(logger.With("pex", i))
 			sw.SetAddrBook(books[i])
diff --git a/p2p/test_util.go b/p2p/test_util.go
index a0b3a5b88..86955f692 100644
--- a/p2p/test_util.go
+++ b/p2p/test_util.go
@@ -1,7 +1,9 @@
 package p2p
 
 import (
+	"fmt"
 	"net"
+	"sync/atomic"
 
 	crypto "github.com/tendermint/go-crypto"
 	cmn "github.com/tendermint/tmlibs/common"
@@ -130,6 +132,8 @@ func StartSwitches(switches []*Switch) error {
 	return nil
 }
 
+var listenAddrSuffix uint32 = 1
+
 func MakeSwitch(cfg *cfg.P2PConfig, i int, network, version string, initSwitch func(int, *Switch) *Switch) *Switch {
 	// new switch, add reactors
 	// TODO: let the config be passed in?
@@ -144,7 +148,7 @@ func MakeSwitch(cfg *cfg.P2PConfig, i int, network, version string, initSwitch f
 		Moniker:    cmn.Fmt("switch%d", i),
 		Network:    network,
 		Version:    version,
-		ListenAddr: cmn.Fmt("%v:%v", network, cmn.RandIntn(64512)+1023),
+		ListenAddr: fmt.Sprintf("127.0.0.%d:%d", atomic.AddUint32(&listenAddrSuffix, 1), cmn.RandIntn(64512)+1023),
 	}
 	for ch := range sw.reactorsByCh {
 		ni.Channels = append(ni.Channels, ch)