diff --git a/internal/ackhandler/received_packet_handler.go b/internal/ackhandler/received_packet_handler.go
index bdb6bb98..b3b73951 100644
--- a/internal/ackhandler/received_packet_handler.go
+++ b/internal/ackhandler/received_packet_handler.go
@@ -34,7 +34,7 @@ const (
 type receivedPacketHandler struct {
 	initialPackets   *receivedPacketTracker
 	handshakePackets *receivedPacketTracker
-	oneRTTPackets    *receivedPacketTracker
+	appDataPackets   *receivedPacketTracker
 }
 
 var _ ReceivedPacketHandler = &receivedPacketHandler{}
@@ -48,7 +48,7 @@ func NewReceivedPacketHandler(
 	return &receivedPacketHandler{
 		initialPackets:   newReceivedPacketTracker(rttStats, logger, version),
 		handshakePackets: newReceivedPacketTracker(rttStats, logger, version),
-		oneRTTPackets:    newReceivedPacketTracker(rttStats, logger, version),
+		appDataPackets:   newReceivedPacketTracker(rttStats, logger, version),
 	}
 }
 
@@ -63,8 +63,9 @@ func (h *receivedPacketHandler) ReceivedPacket(
 		h.initialPackets.ReceivedPacket(pn, rcvTime, shouldInstigateAck)
 	case protocol.EncryptionHandshake:
 		h.handshakePackets.ReceivedPacket(pn, rcvTime, shouldInstigateAck)
-	case protocol.Encryption1RTT:
-		h.oneRTTPackets.ReceivedPacket(pn, rcvTime, shouldInstigateAck)
+	case protocol.Encryption0RTT, protocol.Encryption1RTT:
+		// TODO: implement a check that the client doesn't switch back to 0-RTT after sending a 1-RTT packet
+		h.appDataPackets.ReceivedPacket(pn, rcvTime, shouldInstigateAck)
 	default:
 		panic(fmt.Sprintf("received packet with unknown encryption level: %s", encLevel))
 	}
@@ -72,7 +73,7 @@ func (h *receivedPacketHandler) ReceivedPacket(
 
 // only to be used with 1-RTT packets
 func (h *receivedPacketHandler) IgnoreBelow(pn protocol.PacketNumber) {
-	h.oneRTTPackets.IgnoreBelow(pn)
+	h.appDataPackets.IgnoreBelow(pn)
 }
 
 func (h *receivedPacketHandler) DropPackets(encLevel protocol.EncryptionLevel) {
@@ -94,7 +95,7 @@ func (h *receivedPacketHandler) GetAlarmTimeout() time.Time {
 	if h.handshakePackets != nil {
 		handshakeAlarm = h.handshakePackets.GetAlarmTimeout()
 	}
-	oneRTTAlarm := h.oneRTTPackets.GetAlarmTimeout()
+	oneRTTAlarm := h.appDataPackets.GetAlarmTimeout()
 	return utils.MinNonZeroTime(utils.MinNonZeroTime(initialAlarm, handshakeAlarm), oneRTTAlarm)
 }
 
@@ -110,7 +111,8 @@ func (h *receivedPacketHandler) GetAckFrame(encLevel protocol.EncryptionLevel) *
 			ack = h.handshakePackets.GetAckFrame()
 		}
 	case protocol.Encryption1RTT:
-		return h.oneRTTPackets.GetAckFrame()
+		// 0-RTT packets can't contain ACK frames
+		return h.appDataPackets.GetAckFrame()
 	default:
 		return nil
 	}
diff --git a/internal/ackhandler/received_packet_handler_test.go b/internal/ackhandler/received_packet_handler_test.go
index a057db2b..65edc26b 100644
--- a/internal/ackhandler/received_packet_handler_test.go
+++ b/internal/ackhandler/received_packet_handler_test.go
@@ -48,6 +48,16 @@ var _ = Describe("Received Packet Handler", func() {
 		Expect(oneRTTAck.DelayTime).To(BeNumerically("~", time.Second, 50*time.Millisecond))
 	})
 
+	It("uses the same packet number space for 0-RTT and 1-RTT packets", func() {
+		sendTime := time.Now().Add(-time.Second)
+		handler.ReceivedPacket(2, protocol.Encryption0RTT, sendTime, true)
+		handler.ReceivedPacket(3, protocol.Encryption1RTT, sendTime, true)
+		ack := handler.GetAckFrame(protocol.Encryption1RTT)
+		Expect(ack).ToNot(BeNil())
+		Expect(ack.AckRanges).To(HaveLen(1))
+		Expect(ack.AckRanges[0]).To(Equal(wire.AckRange{Smallest: 2, Largest: 3}))
+	})
+
 	It("drops Initial packets", func() {
 		sendTime := time.Now().Add(-time.Second)
 		handler.ReceivedPacket(2, protocol.EncryptionInitial, sendTime, true)