diff --git a/gossipsub.go b/gossipsub.go
index 7d6714b..3875392 100644
--- a/gossipsub.go
+++ b/gossipsub.go
@@ -71,6 +71,27 @@ func NewGossipSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, er
 	return NewPubSub(ctx, h, rt, opts...)
 }
 
+// WithPeerScore is a gossipsub router option that enables peer scoring.
+func WithPeerScore(params *PeerScoreParams) Option {
+	return func(ps *PubSub) error {
+		gs, ok := ps.rt.(*GossipSubRouter)
+		if !ok {
+			return fmt.Errorf("pubsub router is not gossipsub")
+		}
+
+		gs.score = newPeerScore(gs, params)
+
+		// hook the tracer
+		if ps.tracer != nil {
+			ps.tracer.score = gs.score
+		} else {
+			ps.tracer = &pubsubTracer{score: gs.score, pid: ps.host.ID(), msgID: ps.msgID}
+		}
+
+		return nil
+	}
+}
+
 // GossipSubRouter is a router that implements the gossipsub protocol.
 // For each topic we have joined, we maintain an overlay through which
 // messages flow; this is the mesh map.
@@ -90,6 +111,7 @@ type GossipSubRouter struct {
 	connect chan connectInfo                 // px connection requests
 	mcache  *MessageCache
 	tracer  *pubsubTracer
+	score   *peerScore
 }
 
 type connectInfo struct {
diff --git a/pubsub.go b/pubsub.go
index 151ece8..285b1b7 100644
--- a/pubsub.go
+++ b/pubsub.go
@@ -356,7 +356,11 @@ func WithDiscovery(d discovery.Discovery, opts ...DiscoverOpt) Option {
 // WithEventTracer provides a tracer for the pubsub system
 func WithEventTracer(tracer EventTracer) Option {
 	return func(p *PubSub) error {
-		p.tracer = &pubsubTracer{tracer: tracer, pid: p.host.ID(), msgID: p.msgID}
+		if tracer != nil {
+			p.tracer.tracer = tracer
+		} else {
+			p.tracer = &pubsubTracer{tracer: tracer, pid: p.host.ID(), msgID: p.msgID}
+		}
 		return nil
 	}
 }
diff --git a/score.go b/score.go
new file mode 100644
index 0000000..36839ee
--- /dev/null
+++ b/score.go
@@ -0,0 +1,61 @@
+package pubsub
+
+import (
+	"github.com/libp2p/go-libp2p-core/peer"
+	"github.com/libp2p/go-libp2p-core/protocol"
+)
+
+type peerScore struct {
+}
+
+type PeerScoreParams struct {
+}
+
+type TopicScoreParams struct {
+}
+
+func newPeerScore(gs *GossipSubRouter, params *PeerScoreParams) *peerScore {
+	return nil
+}
+
+// router interface
+func (ps *peerScore) Score(p peer.ID, topic string) float64 {
+	return 0
+}
+
+// tracer interface
+func (ps *peerScore) AddPeer(p peer.ID, proto protocol.ID) {
+
+}
+
+func (ps *peerScore) RemovePeer(p peer.ID) {
+
+}
+
+func (ps *peerScore) Join(topic string) {
+
+}
+
+func (ps *peerScore) Leave(topic string) {
+
+}
+
+func (ps *peerScore) Graft(p peer.ID, topic string) {
+
+}
+
+func (ps *peerScore) Prune(p peer.ID, topic string) {
+
+}
+
+func (ps *peerScore) DeliverMessage(msg *Message) {
+
+}
+
+func (ps *peerScore) RejectMessage(msg *Message, reason string) {
+
+}
+
+func (ps *peerScore) DuplicateMessage(msg *Message) {
+
+}