diff --git a/internal/handshake/transport_parameter_test.go b/internal/handshake/transport_parameter_test.go
index 930e1b6d8..08fcc049f 100644
--- a/internal/handshake/transport_parameter_test.go
+++ b/internal/handshake/transport_parameter_test.go
@@ -53,13 +53,13 @@ var _ = Describe("Transport Parameters", func() {
 		Expect(p.String()).To(Equal("&handshake.TransportParameters{OriginalConnectionID: 0xdeadbeef, InitialMaxStreamDataBidiLocal: 0x1234, InitialMaxStreamDataBidiRemote: 0x2345, InitialMaxStreamDataUni: 0x3456, InitialMaxData: 0x4567, MaxBidiStreams: 1337, MaxUniStreams: 7331, IdleTimeout: 42s, AckDelayExponent: 14, MaxAckDelay: 37s}"))
 	})
 
-	getRandomValue := func() uint64 {
-		maxVals := []int64{math.MaxUint8 / 4, math.MaxUint16 / 4, math.MaxUint32 / 4, math.MaxUint64 / 4}
-		rand.Seed(GinkgoRandomSeed())
-		return uint64(rand.Int63n(maxVals[int(rand.Int31n(4))]))
-	}
-
 	It("marshals and unmarshals", func() {
+		rand.Seed(GinkgoRandomSeed())
+		getRandomValue := func() uint64 {
+			maxVals := []int64{math.MaxUint8 / 4, math.MaxUint16 / 4, math.MaxUint32 / 4, math.MaxUint64 / 4}
+			return uint64(rand.Int63n(maxVals[int(rand.Int31n(4))]))
+		}
+
 		var token [16]byte
 		rand.Read(token[:])
 		params := &TransportParameters{
diff --git a/internal/handshake/transport_parameters.go b/internal/handshake/transport_parameters.go
index 70f748d2b..e8f97624a 100644
--- a/internal/handshake/transport_parameters.go
+++ b/internal/handshake/transport_parameters.go
@@ -205,51 +205,30 @@ func (p *TransportParameters) Marshal() []byte {
 	b.Write([]byte{0, 0}) // length. Will be replaced later
 
 	// initial_max_stream_data_bidi_local
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxStreamDataBidiLocalParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.InitialMaxStreamDataBidiLocal))))
-	utils.WriteVarInt(b, uint64(p.InitialMaxStreamDataBidiLocal))
+	p.marshalVarintParam(b, initialMaxStreamDataBidiLocalParameterID, uint64(p.InitialMaxStreamDataBidiLocal))
 	// initial_max_stream_data_bidi_remote
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxStreamDataBidiRemoteParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.InitialMaxStreamDataBidiRemote))))
-	utils.WriteVarInt(b, uint64(p.InitialMaxStreamDataBidiRemote))
+	p.marshalVarintParam(b, initialMaxStreamDataBidiRemoteParameterID, uint64(p.InitialMaxStreamDataBidiRemote))
 	// initial_max_stream_data_uni
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxStreamDataUniParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.InitialMaxStreamDataUni))))
-	utils.WriteVarInt(b, uint64(p.InitialMaxStreamDataUni))
+	p.marshalVarintParam(b, initialMaxStreamDataUniParameterID, uint64(p.InitialMaxStreamDataUni))
 	// initial_max_data
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxDataParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.InitialMaxData))))
-	utils.WriteVarInt(b, uint64(p.InitialMaxData))
+	p.marshalVarintParam(b, initialMaxDataParameterID, uint64(p.InitialMaxData))
 	// initial_max_bidi_streams
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxStreamsBidiParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(p.MaxBidiStreams)))
-	utils.WriteVarInt(b, p.MaxBidiStreams)
+	p.marshalVarintParam(b, initialMaxStreamsBidiParameterID, p.MaxBidiStreams)
 	// initial_max_uni_streams
-	utils.BigEndian.WriteUint16(b, uint16(initialMaxStreamsUniParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(p.MaxUniStreams)))
-	utils.WriteVarInt(b, p.MaxUniStreams)
+	p.marshalVarintParam(b, initialMaxStreamsUniParameterID, p.MaxUniStreams)
 	// idle_timeout
-	idleTimeout := uint64(p.IdleTimeout / time.Millisecond)
-	utils.BigEndian.WriteUint16(b, uint16(idleTimeoutParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(idleTimeout)))
-	utils.WriteVarInt(b, idleTimeout)
+	p.marshalVarintParam(b, idleTimeoutParameterID, uint64(p.IdleTimeout/time.Millisecond))
 	// max_packet_size
-	utils.BigEndian.WriteUint16(b, uint16(maxPacketSizeParameterID))
-	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(protocol.MaxReceivePacketSize))))
-	utils.WriteVarInt(b, uint64(protocol.MaxReceivePacketSize))
+	p.marshalVarintParam(b, maxPacketSizeParameterID, uint64(protocol.MaxReceivePacketSize))
 	// max_ack_delay
 	// Only send it if is different from the default value.
 	if p.MaxAckDelay != protocol.DefaultMaxAckDelay {
-		utils.BigEndian.WriteUint16(b, uint16(maxAckDelayParameterID))
-		utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.MaxAckDelay/time.Millisecond))))
-		utils.WriteVarInt(b, uint64(p.MaxAckDelay/time.Millisecond))
+		p.marshalVarintParam(b, maxAckDelayParameterID, uint64(p.MaxAckDelay/time.Millisecond))
 	}
 	// ack_delay_exponent
 	// Only send it if is different from the default value.
 	if p.AckDelayExponent != protocol.DefaultAckDelayExponent {
-		utils.BigEndian.WriteUint16(b, uint16(ackDelayExponentParameterID))
-		utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(uint64(p.AckDelayExponent))))
-		utils.WriteVarInt(b, uint64(p.AckDelayExponent))
+		p.marshalVarintParam(b, ackDelayExponentParameterID, uint64(p.AckDelayExponent))
 	}
 	// disable_migration
 	if p.DisableMigration {
@@ -273,6 +252,12 @@ func (p *TransportParameters) Marshal() []byte {
 	return data
 }
 
+func (p *TransportParameters) marshalVarintParam(b *bytes.Buffer, id transportParameterID, val uint64) {
+	utils.BigEndian.WriteUint16(b, uint16(id))
+	utils.BigEndian.WriteUint16(b, uint16(utils.VarIntLen(val)))
+	utils.WriteVarInt(b, val)
+}
+
 // String returns a string representation, intended for logging.
 func (p *TransportParameters) String() string {
 	logString := "&handshake.TransportParameters{OriginalConnectionID: %s, InitialMaxStreamDataBidiLocal: %#x, InitialMaxStreamDataBidiRemote: %#x, InitialMaxStreamDataUni: %#x, InitialMaxData: %#x, MaxBidiStreams: %d, MaxUniStreams: %d, IdleTimeout: %s, AckDelayExponent: %d, MaxAckDelay: %s"