diff --git a/f3-sidecar/go.mod b/f3-sidecar/go.mod
index 5886251442b..da504c7f835 100644
--- a/f3-sidecar/go.mod
+++ b/f3-sidecar/go.mod
@@ -14,6 +14,7 @@ require (
 	github.com/libp2p/go-libp2p-kad-dht v0.33.1
 	github.com/libp2p/go-libp2p-pubsub v0.14.0
 	github.com/stretchr/testify v1.10.0
+	golang.org/x/crypto v0.39.0
 )
 
 require (
@@ -135,7 +136,6 @@ require (
 	go.uber.org/mock v0.5.2 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.27.0 // indirect
-	golang.org/x/crypto v0.39.0 // indirect
 	golang.org/x/exp v0.0.0-20250606033433-dcc06ee1d476 // indirect
 	golang.org/x/mod v0.25.0 // indirect
 	golang.org/x/net v0.41.0 // indirect
diff --git a/f3-sidecar/p2p.go b/f3-sidecar/p2p.go
index 7818e71d7e0..d8bfeb1601a 100644
--- a/f3-sidecar/p2p.go
+++ b/f3-sidecar/p2p.go
@@ -7,8 +7,10 @@ import (
 	"github.com/libp2p/go-libp2p"
 	dht "github.com/libp2p/go-libp2p-kad-dht"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	pubsub_pb "github.com/libp2p/go-libp2p-pubsub/pb"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/protocol"
+	"golang.org/x/crypto/blake2b"
 )
 
 const ListenAddr = "/ip4/127.0.0.1/tcp/0"
@@ -51,6 +53,16 @@ func createP2PHost(ctx context.Context, networkName string) (*P2PHost, error) {
 	ps, err := pubsub.NewGossipSub(ctx, host,
 		pubsub.WithPeerExchange(true),
 		pubsub.WithFloodPublish(true),
+		pubsub.WithMessageIdFn(hashMsgId),
+		// Bump the validation queue to accommodate the increase in gossipsub message
+		// exchange rate as a result of f3. The size of 256 should offer enough headroom
+		// for slower F3 validation while avoiding: 1) avoid excessive memory usage, 2)
+		// dropped consensus related messages and 3) cascading effect among other topics
+		// since this config isn't topic-specific.
+		//
+		// Note that the worst case memory footprint is 256 MiB based on the default
+		// message size of 1 MiB, which isn't overridden in Lotus.
+		pubsub.WithValidateQueueSize(256),
 		pubsub.WithPeerScore(PubsubPeerScoreParams, PubsubPeerScoreThresholds))
 	if err != nil {
 		return nil, err
@@ -58,3 +70,8 @@ func createP2PHost(ctx context.Context, networkName string) (*P2PHost, error) {
 
 	return &P2PHost{host, hostDHT, backupHostDHT, ps}, nil
 }
+
+func hashMsgId(m *pubsub_pb.Message) string {
+	hash := blake2b.Sum256(m.Data)
+	return string(hash[:])
+}