diff --git a/entropy_accumulator.go b/ackhandler/entropy_accumulator.go
similarity index 96%
rename from entropy_accumulator.go
rename to ackhandler/entropy_accumulator.go
index 14594eef1..fe120571e 100644
--- a/entropy_accumulator.go
+++ b/ackhandler/entropy_accumulator.go
@@ -1,4 +1,4 @@
-package quic
+package ackhandler
 
 import "github.com/lucas-clemente/quic-go/protocol"
 
diff --git a/entropy_accumulator_test.go b/ackhandler/entropy_accumulator_test.go
similarity index 96%
rename from entropy_accumulator_test.go
rename to ackhandler/entropy_accumulator_test.go
index 5b149a227..adb7f0974 100644
--- a/entropy_accumulator_test.go
+++ b/ackhandler/entropy_accumulator_test.go
@@ -1,4 +1,4 @@
-package quic
+package ackhandler
 
 import (
 	. "github.com/onsi/ginkgo"
diff --git a/session.go b/session.go
index 4321ddbcc..dd7eec5b9 100644
--- a/session.go
+++ b/session.go
@@ -8,6 +8,7 @@ import (
 	"net"
 	"sync"
 
+	"github.com/lucas-clemente/quic-go/ackhandler"
 	"github.com/lucas-clemente/quic-go/errorcodes"
 	"github.com/lucas-clemente/quic-go/frames"
 	"github.com/lucas-clemente/quic-go/handshake"
@@ -29,9 +30,9 @@ type Session struct {
 	ServerConfig *handshake.ServerConfig
 	cryptoSetup  *handshake.CryptoSetup
 
-	EntropyReceived     EntropyAccumulator
-	EntropySent         EntropyAccumulator
-	EntropyHistory      map[protocol.PacketNumber]EntropyAccumulator // ToDo: store this with the packet itself
+	EntropyReceived     ackhandler.EntropyAccumulator
+	EntropySent         ackhandler.EntropyAccumulator
+	EntropyHistory      map[protocol.PacketNumber]ackhandler.EntropyAccumulator // ToDo: store this with the packet itself
 	entropyHistoryMutex sync.Mutex
 
 	lastSentPacketNumber     protocol.PacketNumber
@@ -55,7 +56,7 @@ func NewSession(conn *net.UDPConn, v protocol.VersionNumber, connectionID protoc
 		streamCallback:           streamCallback,
 		lastObservedPacketNumber: 0,
 		Streams:                  make(map[protocol.StreamID]*Stream),
-		EntropyHistory:           make(map[protocol.PacketNumber]EntropyAccumulator),
+		EntropyHistory:           make(map[protocol.PacketNumber]ackhandler.EntropyAccumulator),
 	}
 
 	cryptoStream, _ := session.NewStream(1)