diff --git a/ackhandlernew/stop_waiting_manager.go b/ackhandlernew/stop_waiting_manager.go
index e37d84e5..38b9564b 100644
--- a/ackhandlernew/stop_waiting_manager.go
+++ b/ackhandlernew/stop_waiting_manager.go
@@ -30,7 +30,6 @@ func (h *stopWaitingManager) RegisterPacketForRetransmission(packet *Packet) {
 	if h.currentStopWaitingFrame == nil || h.currentStopWaitingFrame.LeastUnacked <= packet.PacketNumber { // <= because for StopWaitingFrames LeastUnacked = packet.PacketNumber + 1
 		h.currentStopWaitingFrame = &frames.StopWaitingFrame{
 			LeastUnacked: packet.PacketNumber + 1,
-			Entropy:      byte(packet.Entropy),
 		}
 		h.maxRetransmittedPacketNumber = packet.PacketNumber
 		h.currentStopWaitingFrameSent = false
diff --git a/ackhandlernew/stop_waiting_manager_test.go b/ackhandlernew/stop_waiting_manager_test.go
index fa15d57a..0bc44719 100644
--- a/ackhandlernew/stop_waiting_manager_test.go
+++ b/ackhandlernew/stop_waiting_manager_test.go
@@ -18,39 +18,36 @@ var _ = Describe("StopWaitingManager", func() {
 
 	It("gets a StopWaitingFrame after a packet has been registered for retransmission", func() {
 		leastUnacked := protocol.PacketNumber(10)
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked, Entropy: 10})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked})
 		swf := manager.GetStopWaitingFrame()
 		Expect(swf).ToNot(BeNil())
 		Expect(swf.LeastUnacked).To(Equal(leastUnacked + 1))
-		Expect(swf.Entropy).To(Equal(byte(10)))
 	})
 
 	It("always gets the StopWaitingFrame for the highest retransmitted packet number", func() {
 		leastUnacked := protocol.PacketNumber(10)
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked, Entropy: 10})
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1, Entropy: 8})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1})
 		swf := manager.GetStopWaitingFrame()
 		Expect(swf).ToNot(BeNil())
 		Expect(swf.LeastUnacked).To(Equal(leastUnacked + 1))
-		Expect(swf.Entropy).To(Equal(byte(10)))
 	})
 
 	It("updates the StopWaitingFrame when a packet with a higher packet number is retransmitted", func() {
 		leastUnacked := protocol.PacketNumber(10)
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1, Entropy: 10})
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked, Entropy: 8})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked})
 		swf := manager.GetStopWaitingFrame()
 		Expect(swf).ToNot(BeNil())
 		Expect(swf.LeastUnacked).To(Equal(leastUnacked + 1))
-		Expect(swf.Entropy).To(Equal(byte(8)))
 	})
 
 	It("does not create a new StopWaitingFrame for an out-of-order retransmission", func() {
 		leastUnacked := protocol.PacketNumber(10)
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked, Entropy: 8})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked})
 		manager.SentStopWaitingWithPacket(12)
 		manager.ReceivedAckForPacketNumber(12)
-		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1, Entropy: 10})
+		manager.RegisterPacketForRetransmission(&Packet{PacketNumber: leastUnacked - 1})
 		swf := manager.GetStopWaitingFrame()
 		Expect(swf).To(BeNil())
 	})