diff --git a/internal/ackhandler/interfaces.go b/internal/ackhandler/interfaces.go
index 372c59a4..c7006f7d 100644
--- a/internal/ackhandler/interfaces.go
+++ b/internal/ackhandler/interfaces.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/wire"
+	"github.com/lucas-clemente/quic-go/quictrace"
 )
 
 // SentPacketHandler handles ACKs received for outgoing packets
@@ -41,7 +42,7 @@ type SentPacketHandler interface {
 	OnAlarm() error
 
 	// report some congestion statistics. For tracing only.
-	GetStats() *State
+	GetStats() *quictrace.TransportState
 }
 
 // ReceivedPacketHandler handles ACKs needed to send for incoming packets
@@ -53,12 +54,3 @@ type ReceivedPacketHandler interface {
 	GetAlarmTimeout() time.Time
 	GetAckFrame(protocol.EncryptionLevel) *wire.AckFrame
 }
-
-type State struct {
-	MinRTT      time.Duration
-	SmoothedRTT time.Duration
-	LatestRTT   time.Duration
-
-	BytesInFlight    protocol.ByteCount
-	CongestionWindow protocol.ByteCount
-}
diff --git a/internal/ackhandler/sent_packet_handler.go b/internal/ackhandler/sent_packet_handler.go
index 30842c41..2a8564a0 100644
--- a/internal/ackhandler/sent_packet_handler.go
+++ b/internal/ackhandler/sent_packet_handler.go
@@ -11,6 +11,7 @@ import (
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
+	"github.com/lucas-clemente/quic-go/quictrace"
 )
 
 const (
@@ -671,8 +672,8 @@ func (h *sentPacketHandler) ResetForRetry() error {
 	return nil
 }
 
-func (h *sentPacketHandler) GetStats() *State {
-	return &State{
+func (h *sentPacketHandler) GetStats() *quictrace.TransportState {
+	return &quictrace.TransportState{
 		MinRTT:           h.rttStats.MinRTT(),
 		SmoothedRTT:      h.rttStats.SmoothedOrInitialRTT(),
 		LatestRTT:        h.rttStats.LatestRTT(),
diff --git a/internal/mockgen_internal.sh b/internal/mockgen_internal.sh
index a0f9112b..240611ee 100755
--- a/internal/mockgen_internal.sh
+++ b/internal/mockgen_internal.sh
@@ -7,13 +7,14 @@
 # Afterwards, it corrects the import paths (replaces internalpackage back to internal).
 
 TEMP_DIR=$(mktemp -d)
-mkdir -p $TEMP_DIR/src/github.com/lucas-clemente/quic-go/internalpackage
+mkdir -p $TEMP_DIR/src/github.com/lucas-clemente/quic-go/
 
 # uppercase the name of the interface (only has an effect for private interfaces)
 INTERFACE_NAME="$(tr '[:lower:]' '[:upper:]' <<< ${4:0:1})${4:1}"
 PACKAGE_NAME=`echo $3 | sed 's/.*\///'`
 
-cp -r $GOPATH/src/github.com/lucas-clemente/quic-go/internal/* $TEMP_DIR/src/github.com/lucas-clemente/quic-go/internalpackage
+rsync -a $GOPATH/src/github.com/lucas-clemente/quic-go/* $TEMP_DIR/src/github.com/lucas-clemente/quic-go/ --exclude example
+mv $TEMP_DIR/src/github.com/lucas-clemente/quic-go/internal $TEMP_DIR/src/github.com/lucas-clemente/quic-go/internalpackage
 find $TEMP_DIR -type f -name "*.go" -exec sed -i '' 's/internal/internalpackage/g' {} \;
 
 export GOPATH="$TEMP_DIR:$GOPATH"
diff --git a/internal/mocks/ackhandler/sent_packet_handler.go b/internal/mocks/ackhandler/sent_packet_handler.go
index 34a5ee61..82f7bcaa 100644
--- a/internal/mocks/ackhandler/sent_packet_handler.go
+++ b/internal/mocks/ackhandler/sent_packet_handler.go
@@ -12,6 +12,7 @@ import (
 	ackhandler "github.com/lucas-clemente/quic-go/internal/ackhandler"
 	protocol "github.com/lucas-clemente/quic-go/internal/protocol"
 	wire "github.com/lucas-clemente/quic-go/internal/wire"
+	quictrace "github.com/lucas-clemente/quic-go/quictrace"
 )
 
 // MockSentPacketHandler is a mock of SentPacketHandler interface
@@ -107,10 +108,10 @@ func (mr *MockSentPacketHandlerMockRecorder) GetLowestPacketNotConfirmedAcked()
 }
 
 // GetStats mocks base method
-func (m *MockSentPacketHandler) GetStats() *ackhandler.State {
+func (m *MockSentPacketHandler) GetStats() *quictrace.TransportState {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "GetStats")
-	ret0, _ := ret[0].(*ackhandler.State)
+	ret0, _ := ret[0].(*quictrace.TransportState)
 	return ret0
 }
 
diff --git a/quictrace/interface.go b/quictrace/interface.go
index 3e71a443..83781bd2 100644
--- a/quictrace/interface.go
+++ b/quictrace/interface.go
@@ -3,7 +3,6 @@ package quictrace
 import (
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/ackhandler"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 )
@@ -31,9 +30,19 @@ type Event struct {
 	Time      time.Time
 	EventType EventType
 
-	TransportState  *ackhandler.State
+	TransportState  *TransportState
 	EncryptionLevel protocol.EncryptionLevel
 	PacketNumber    protocol.PacketNumber
 	PacketSize      protocol.ByteCount
 	Frames          []wire.Frame
 }
+
+// TransportState contains some transport and congestion statistics
+type TransportState struct {
+	MinRTT      time.Duration
+	SmoothedRTT time.Duration
+	LatestRTT   time.Duration
+
+	BytesInFlight    protocol.ByteCount
+	CongestionWindow protocol.ByteCount
+}
diff --git a/quictrace/tracer.go b/quictrace/tracer.go
index 96135951..4bcc706a 100644
--- a/quictrace/tracer.go
+++ b/quictrace/tracer.go
@@ -6,7 +6,6 @@ import (
 
 	"github.com/golang/protobuf/proto"
 
-	"github.com/lucas-clemente/quic-go/internal/ackhandler"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 	"github.com/lucas-clemente/quic-go/quictrace/pb"
@@ -171,7 +170,7 @@ func getFrames(wframes []wire.Frame) []*pb.Frame {
 	return frames
 }
 
-func getTransportState(state *ackhandler.State) *pb.TransportState {
+func getTransportState(state *TransportState) *pb.TransportState {
 	bytesInFlight := uint64(state.BytesInFlight)
 	congestionWindow := uint64(state.CongestionWindow)
 	return &pb.TransportState{