diff --git a/beacon-chain/p2p/encoder/ssz.go b/beacon-chain/p2p/encoder/ssz.go
index 5a0ac1cdc..001ff674f 100644
--- a/beacon-chain/p2p/encoder/ssz.go
+++ b/beacon-chain/p2p/encoder/ssz.go
@@ -99,14 +99,14 @@ func (e SszNetworkEncoder) doDecode(b []byte, to interface{}) error {
 
 // DecodeGossip decodes the bytes to the protobuf gossip message provided.
 func (e SszNetworkEncoder) DecodeGossip(b []byte, to interface{}) error {
-	var err error
+	size, err := snappy.DecodedLen(b)
+	if uint64(size) > MaxGossipSize {
+		return errors.Errorf("gossip message exceeds max gossip size: %d bytes > %d bytes", size, MaxGossipSize)
+	}
 	b, err = snappy.Decode(nil /*dst*/, b)
 	if err != nil {
 		return err
 	}
-	if uint64(len(b)) > MaxGossipSize {
-		return errors.Errorf("gossip message exceeds max gossip size: %d bytes > %d bytes", len(b), MaxGossipSize)
-	}
 	return e.doDecode(b, to)
 }
 
diff --git a/beacon-chain/p2p/encoder/ssz_test.go b/beacon-chain/p2p/encoder/ssz_test.go
index a0e74bead..8f44d3697 100644
--- a/beacon-chain/p2p/encoder/ssz_test.go
+++ b/beacon-chain/p2p/encoder/ssz_test.go
@@ -2,6 +2,7 @@ package encoder_test
 
 import (
 	"bytes"
+	"encoding/binary"
 	"fmt"
 	"testing"
 
@@ -19,10 +20,13 @@ func TestSszNetworkEncoder_RoundTrip(t *testing.T) {
 	testRoundTripWithGossip(t, e)
 }
 
-func TestSszNetworkEncoder_RoundTrip_Snappy(t *testing.T) {
+func TestSszNetworkEncoder_FailsSnappyLength(t *testing.T) {
 	e := &encoder.SszNetworkEncoder{}
-	testRoundTripWithLength(t, e)
-	testRoundTripWithGossip(t, e)
+	att := &testpb.TestSimpleMessage{}
+	data := make([]byte, 32)
+	binary.PutUvarint(data, encoder.MaxGossipSize+32)
+	err := e.DecodeGossip(data, att)
+	require.ErrorContains(t, "gossip message exceeds max gossip size", err)
 }
 
 func testRoundTripWithLength(t *testing.T, e *encoder.SszNetworkEncoder) {