diff --git a/internal/ackhandler/interfaces.go b/internal/ackhandler/interfaces.go
index 4f667ac3f..b1abad0ab 100644
--- a/internal/ackhandler/interfaces.go
+++ b/internal/ackhandler/interfaces.go
@@ -45,6 +45,7 @@ type SentPacketHandler interface {
 type ReceivedPacketHandler interface {
 	ReceivedPacket(pn protocol.PacketNumber, encLevel protocol.EncryptionLevel, rcvTime time.Time, shouldInstigateAck bool) error
 	IgnoreBelow(protocol.PacketNumber)
+	DropPackets(protocol.EncryptionLevel)
 
 	GetAlarmTimeout() time.Time
 	GetAckFrame(protocol.EncryptionLevel) *wire.AckFrame
diff --git a/internal/ackhandler/received_packet_handler.go b/internal/ackhandler/received_packet_handler.go
index b457fb4b0..1035bd12f 100644
--- a/internal/ackhandler/received_packet_handler.go
+++ b/internal/ackhandler/received_packet_handler.go
@@ -75,9 +75,25 @@ func (h *receivedPacketHandler) IgnoreBelow(pn protocol.PacketNumber) {
 	h.oneRTTPackets.IgnoreBelow(pn)
 }
 
+func (h *receivedPacketHandler) DropPackets(encLevel protocol.EncryptionLevel) {
+	switch encLevel {
+	case protocol.EncryptionInitial:
+		h.initialPackets = nil
+	case protocol.EncryptionHandshake:
+		h.handshakePackets = nil
+	default:
+		panic(fmt.Sprintf("Cannot drop keys for encryption level %s", encLevel))
+	}
+}
+
 func (h *receivedPacketHandler) GetAlarmTimeout() time.Time {
-	initialAlarm := h.initialPackets.GetAlarmTimeout()
-	handshakeAlarm := h.handshakePackets.GetAlarmTimeout()
+	var initialAlarm, handshakeAlarm time.Time
+	if h.initialPackets != nil {
+		initialAlarm = h.initialPackets.GetAlarmTimeout()
+	}
+	if h.handshakePackets != nil {
+		handshakeAlarm = h.handshakePackets.GetAlarmTimeout()
+	}
 	oneRTTAlarm := h.oneRTTPackets.GetAlarmTimeout()
 	return utils.MinNonZeroTime(utils.MinNonZeroTime(initialAlarm, handshakeAlarm), oneRTTAlarm)
 }
@@ -86,9 +102,13 @@ func (h *receivedPacketHandler) GetAckFrame(encLevel protocol.EncryptionLevel) *
 	var ack *wire.AckFrame
 	switch encLevel {
 	case protocol.EncryptionInitial:
-		ack = h.initialPackets.GetAckFrame()
+		if h.initialPackets != nil {
+			ack = h.initialPackets.GetAckFrame()
+		}
 	case protocol.EncryptionHandshake:
-		ack = h.handshakePackets.GetAckFrame()
+		if h.handshakePackets != nil {
+			ack = h.handshakePackets.GetAckFrame()
+		}
 	case protocol.Encryption1RTT:
 		return h.oneRTTPackets.GetAckFrame()
 	default:
diff --git a/internal/ackhandler/received_packet_handler_test.go b/internal/ackhandler/received_packet_handler_test.go
index 80a26b7f9..7bcea8e34 100644
--- a/internal/ackhandler/received_packet_handler_test.go
+++ b/internal/ackhandler/received_packet_handler_test.go
@@ -47,4 +47,24 @@ var _ = Describe("Received Packet Handler", func() {
 		Expect(oneRTTAck.AckRanges[0]).To(Equal(wire.AckRange{Smallest: 4, Largest: 5}))
 		Expect(oneRTTAck.DelayTime).To(BeNumerically("~", time.Second, 50*time.Millisecond))
 	})
+
+	It("drops Initial packets", func() {
+		sendTime := time.Now().Add(-time.Second)
+		Expect(handler.ReceivedPacket(2, protocol.EncryptionInitial, sendTime, true)).To(Succeed())
+		Expect(handler.ReceivedPacket(1, protocol.EncryptionHandshake, sendTime, true)).To(Succeed())
+		Expect(handler.GetAckFrame(protocol.EncryptionInitial)).ToNot(BeNil())
+		handler.DropPackets(protocol.EncryptionInitial)
+		Expect(handler.GetAckFrame(protocol.EncryptionInitial)).To(BeNil())
+		Expect(handler.GetAckFrame(protocol.EncryptionHandshake)).ToNot(BeNil())
+	})
+
+	It("drops Handshake packets", func() {
+		sendTime := time.Now().Add(-time.Second)
+		Expect(handler.ReceivedPacket(1, protocol.EncryptionHandshake, sendTime, true)).To(Succeed())
+		Expect(handler.ReceivedPacket(2, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
+		Expect(handler.GetAckFrame(protocol.EncryptionHandshake)).ToNot(BeNil())
+		handler.DropPackets(protocol.EncryptionInitial)
+		Expect(handler.GetAckFrame(protocol.EncryptionHandshake)).To(BeNil())
+		Expect(handler.GetAckFrame(protocol.Encryption1RTT)).ToNot(BeNil())
+	})
 })
diff --git a/internal/mocks/ackhandler/received_packet_handler.go b/internal/mocks/ackhandler/received_packet_handler.go
index 4c395f27e..640b725a4 100644
--- a/internal/mocks/ackhandler/received_packet_handler.go
+++ b/internal/mocks/ackhandler/received_packet_handler.go
@@ -36,6 +36,18 @@ func (m *MockReceivedPacketHandler) EXPECT() *MockReceivedPacketHandlerMockRecor
 	return m.recorder
 }
 
+// DropPackets mocks base method
+func (m *MockReceivedPacketHandler) DropPackets(arg0 protocol.EncryptionLevel) {
+	m.ctrl.T.Helper()
+	m.ctrl.Call(m, "DropPackets", arg0)
+}
+
+// DropPackets indicates an expected call of DropPackets
+func (mr *MockReceivedPacketHandlerMockRecorder) DropPackets(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "DropPackets", reflect.TypeOf((*MockReceivedPacketHandler)(nil).DropPackets), arg0)
+}
+
 // GetAckFrame mocks base method
 func (m *MockReceivedPacketHandler) GetAckFrame(arg0 protocol.EncryptionLevel) *wire.AckFrame {
 	m.ctrl.T.Helper()