diff --git a/libs/pubsub/pubsub.go b/libs/pubsub/pubsub.go
index 6e86a63c9..8d4d1fb05 100644
--- a/libs/pubsub/pubsub.go
+++ b/libs/pubsub/pubsub.go
@@ -88,6 +88,8 @@ type Server struct {
 	cmds    chan cmd
 	cmdsCap int
 
+	// check if we have subscription before
+	// subscribing or unsubscribing
 	mtx           sync.RWMutex
 	subscriptions map[string]map[string]struct{} // subscriber -> query (string) -> empty struct
 }
diff --git a/p2p/switch.go b/p2p/switch.go
index 7d2e6c3f3..ccd6d40f2 100644
--- a/p2p/switch.go
+++ b/p2p/switch.go
@@ -645,43 +645,36 @@ func (sw *Switch) addPeer(p Peer) error {
 
 	// Handle the shut down case where the switch has stopped but we're
 	// concurrently trying to add a peer.
-	if sw.IsRunning() {
-		// All good. Start peer
-		if err := sw.startInitPeer(p); err != nil {
-			return err
-		}
-	} else {
+	if !sw.IsRunning() {
+		// XXX should this return an error or just log and terminate?
 		sw.Logger.Error("Won't start a peer - switch is not running", "peer", p)
+		return nil
 	}
 
-	// Add the peer to .peers.
-	// We start it first so that a peer in the list is safe to Stop.
-	// It should not err since we already checked peers.Has().
-	if err := sw.peers.Add(p); err != nil {
+	// Start the peer's send/recv routines.
+	// Must start it before adding it to the peer set
+	// to prevent Start and Stop from being called concurrently.
+	err := p.Start()
+	if err != nil {
+		// Should never happen
+		sw.Logger.Error("Error starting peer", "err", err, "peer", p)
 		return err
 	}
 
-	sw.Logger.Info("Added peer", "peer", p)
-	sw.metrics.Peers.Add(float64(1))
-
-	return nil
-}
-
-func (sw *Switch) startInitPeer(p Peer) error {
-	err := p.Start() // spawn send/recv routines
-	if err != nil {
-		// Should never happen
-		sw.Logger.Error(
-			"Error starting peer",
-			"err", err,
-			"peer", p,
-		)
+	// Add the peer to PeerSet. Do this before starting the reactors
+	// so that if Receive errors, we will find the peer and remove it.
+	// Add should not err since we already checked peers.Has().
+	if err := sw.peers.Add(p); err != nil {
 		return err
 	}
+	sw.metrics.Peers.Add(float64(1))
 
+	// Start all the reactor protocols on the peer.
 	for _, reactor := range sw.reactors {
 		reactor.AddPeer(p)
 	}
 
+	sw.Logger.Info("Added peer", "peer", p)
+
 	return nil
 }
diff --git a/p2p/switch_test.go b/p2p/switch_test.go
index 358661616..47cfed55f 100644
--- a/p2p/switch_test.go
+++ b/p2p/switch_test.go
@@ -273,6 +273,8 @@ func TestSwitchPeerFilterTimeout(t *testing.T) {
 
 func TestSwitchPeerFilterDuplicate(t *testing.T) {
 	sw := MakeSwitch(cfg, 1, "testing", "123.123.123", initSwitchFunc)
+	sw.Start()
+	defer sw.Stop()
 
 	// simulate remote peer
 	rp := &remotePeer{PrivKey: ed25519.GenPrivKey(), Config: cfg}
@@ -293,12 +295,12 @@ func TestSwitchPeerFilterDuplicate(t *testing.T) {
 	}
 
 	err = sw.addPeer(p)
-	if err, ok := err.(ErrRejected); ok {
-		if !err.IsDuplicate() {
-			t.Errorf("expected peer to be duplicate")
+	if errRej, ok := err.(ErrRejected); ok {
+		if !errRej.IsDuplicate() {
+			t.Errorf("expected peer to be duplicate. got %v", errRej)
 		}
 	} else {
-		t.Errorf("expected ErrRejected")
+		t.Errorf("expected ErrRejected, got %v", err)
 	}
 }