diff --git a/ackhandler/sent_packet_handler.go b/ackhandler/sent_packet_handler.go
index 320f81a9..179a1e1b 100644
--- a/ackhandler/sent_packet_handler.go
+++ b/ackhandler/sent_packet_handler.go
@@ -310,10 +310,11 @@ func (h *sentPacketHandler) DequeuePacketForRetransmission() *Packet {
 	if len(h.retransmissionQueue) == 0 {
 		return nil
 	}
-	queueLen := len(h.retransmissionQueue)
-	// packets are usually NACKed in descending order. So use the slice as a stack
-	packet := h.retransmissionQueue[queueLen-1]
-	h.retransmissionQueue = h.retransmissionQueue[:queueLen-1]
+	packet := h.retransmissionQueue[0]
+	// Shift the slice and don't retain anything that isn't needed.
+	copy(h.retransmissionQueue, h.retransmissionQueue[1:])
+	h.retransmissionQueue[len(h.retransmissionQueue)-1] = nil
+	h.retransmissionQueue = h.retransmissionQueue[:len(h.retransmissionQueue)-1]
 	return packet
 }
 
diff --git a/ackhandler/sent_packet_handler_test.go b/ackhandler/sent_packet_handler_test.go
index cd531fb1..2e5d7fae 100644
--- a/ackhandler/sent_packet_handler_test.go
+++ b/ackhandler/sent_packet_handler_test.go
@@ -777,8 +777,12 @@ var _ = Describe("SentPacketHandler", func() {
 			Expect(handler.GetAlarmTimeout().Sub(time.Now())).To(BeNumerically("~", handler.computeRTOTimeout(), time.Minute))
 
 			handler.OnAlarm()
-			Expect(handler.DequeuePacketForRetransmission()).ToNot(BeNil())
-			Expect(handler.DequeuePacketForRetransmission()).ToNot(BeNil())
+			p := handler.DequeuePacketForRetransmission()
+			Expect(p).ToNot(BeNil())
+			Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(1)))
+			p = handler.DequeuePacketForRetransmission()
+			Expect(p).ToNot(BeNil())
+			Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(2)))
 
 			Expect(handler.rtoCount).To(BeEquivalentTo(1))
 		})