diff --git a/ackhandler/received_packet_handler.go b/ackhandler/received_packet_handler.go
index 4f804e60..112c079d 100644
--- a/ackhandler/received_packet_handler.go
+++ b/ackhandler/received_packet_handler.go
@@ -12,6 +12,8 @@ import (
 var (
 	// ErrDuplicatePacket occurres when a duplicate packet is received
 	ErrDuplicatePacket = errors.New("ReceivedPacketHandler: Duplicate Packet")
+	// ErrMapAccess occurs when a NACK contains invalid NACK ranges
+	ErrMapAccess = qerr.Error(qerr.InvalidAckData, "Packet does not exist in PacketHistory")
 	// ErrPacketSmallerThanLastStopWaiting occurs when a packet arrives with a packet number smaller than the largest LeastUnacked of a StopWaitingFrame. If this error occurs, the packet should be ignored
 	ErrPacketSmallerThanLastStopWaiting = errors.New("ReceivedPacketHandler: Packet number smaller than highest StopWaiting")
 )
diff --git a/ackhandler/sent_packet_handler.go b/ackhandler/sent_packet_handler.go
index 453341e1..c21ad189 100644
--- a/ackhandler/sent_packet_handler.go
+++ b/ackhandler/sent_packet_handler.go
@@ -15,10 +15,6 @@ import (
 var (
 	// ErrDuplicateOrOutOfOrderAck occurs when a duplicate or an out-of-order ACK is received
 	ErrDuplicateOrOutOfOrderAck = errors.New("SentPacketHandler: Duplicate or out-of-order ACK")
-	// ErrEntropy occurs when an ACK with incorrect entropy is received
-	ErrEntropy = qerr.Error(qerr.InvalidAckData, "wrong entropy")
-	// ErrMapAccess occurs when a NACK contains invalid NACK ranges
-	ErrMapAccess = qerr.Error(qerr.InvalidAckData, "Packet does not exist in PacketHistory")
 	// ErrTooManyTrackedSentPackets occurs when the sentPacketHandler has to keep track of too many packets
 	ErrTooManyTrackedSentPackets = errors.New("Too many outstanding non-acked and non-retransmitted packets")
 	errAckForUnsentPacket        = qerr.Error(qerr.InvalidAckData, "Received ACK for an unsent package")