diff --git a/packet_packer.go b/packet_packer.go
index 858fcd71..6599a277 100644
--- a/packet_packer.go
+++ b/packet_packer.go
@@ -156,6 +156,7 @@ type packetPacker struct {
 	pnManager           packetNumberManager
 	framer              frameSource
 	acks                ackFrameSource
+	datagramQueue       *datagramQueue
 	retransmissionQueue *retransmissionQueue
 
 	maxPacketSize          protocol.ByteCount
@@ -175,6 +176,7 @@ func newPacketPacker(
 	cryptoSetup sealingManager,
 	framer frameSource,
 	acks ackFrameSource,
+	datagramQueue *datagramQueue,
 	perspective protocol.Perspective,
 	version protocol.VersionNumber,
 ) *packetPacker {
@@ -185,6 +187,7 @@ func newPacketPacker(
 		initialStream:       initialStream,
 		handshakeStream:     handshakeStream,
 		retransmissionQueue: retransmissionQueue,
+		datagramQueue:       datagramQueue,
 		perspective:         perspective,
 		version:             version,
 		framer:              framer,
@@ -576,10 +579,25 @@ func (p *packetPacker) maybeGetAppDataPacketWithEncLevel(maxPayloadSize protocol
 
 func (p *packetPacker) composeNextPacket(maxFrameSize protocol.ByteCount, ackAllowed bool) *payload {
 	payload := &payload{}
+
+	var hasDatagram bool
+	if p.datagramQueue != nil {
+		if datagram := p.datagramQueue.Get(); datagram != nil {
+			payload.frames = append(payload.frames, ackhandler.Frame{
+				Frame: datagram,
+				// set it to a no-op. Then we won't set the default callback, which would retransmit the frame.
+				OnLost: func(wire.Frame) {},
+			})
+			payload.length += datagram.Length(p.version)
+			hasDatagram = true
+		}
+	}
+
 	var ack *wire.AckFrame
 	hasData := p.framer.HasData()
 	hasRetransmission := p.retransmissionQueue.HasAppData()
-	if ackAllowed {
+	// TODO: make sure ACKs are sent when a lot of DATAGRAMs are queued
+	if !hasDatagram && ackAllowed {
 		ack = p.acks.GetAckFrame(protocol.Encryption1RTT, !hasRetransmission && !hasData)
 		if ack != nil {
 			payload.ack = ack
diff --git a/packet_packer_test.go b/packet_packer_test.go
index 49c9f23b..92b883d3 100644
--- a/packet_packer_test.go
+++ b/packet_packer_test.go
@@ -7,17 +7,16 @@ import (
 	"net"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/qerr"
-
 	"github.com/lucas-clemente/quic-go/internal/ackhandler"
-
-	"github.com/golang/mock/gomock"
 	"github.com/lucas-clemente/quic-go/internal/handshake"
 	"github.com/lucas-clemente/quic-go/internal/mocks"
 	mockackhandler "github.com/lucas-clemente/quic-go/internal/mocks/ackhandler"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 
+	"github.com/golang/mock/gomock"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/ginkgo/extensions/table"
 	. "github.com/onsi/gomega"
@@ -30,6 +29,7 @@ var _ = Describe("Packet packer", func() {
 	var (
 		packer              *packetPacker
 		retransmissionQueue *retransmissionQueue
+		datagramQueue       *datagramQueue
 		framer              *MockFrameSource
 		ackFramer           *MockAckFrameSource
 		initialStream       *MockCryptoStream
@@ -90,6 +90,7 @@ var _ = Describe("Packet packer", func() {
 		ackFramer = NewMockAckFrameSource(mockCtrl)
 		sealingManager = NewMockSealingManager(mockCtrl)
 		pnManager = mockackhandler.NewMockSentPacketHandler(mockCtrl)
+		datagramQueue = newDatagramQueue(func() {})
 
 		packer = newPacketPacker(
 			protocol.ConnectionID{1, 2, 3, 4, 5, 6, 7, 8},
@@ -102,6 +103,7 @@ var _ = Describe("Packet packer", func() {
 			sealingManager,
 			framer,
 			ackFramer,
+			datagramQueue,
 			protocol.PerspectiveServer,
 			version,
 		)
@@ -537,6 +539,33 @@ var _ = Describe("Packet packer", func() {
 				Expect(p.buffer.Len()).ToNot(BeZero())
 			})
 
+			It("packs DATAGRAM frames", func() {
+				pnManager.EXPECT().PeekPacketNumber(protocol.Encryption1RTT).Return(protocol.PacketNumber(0x42), protocol.PacketNumberLen2)
+				pnManager.EXPECT().PopPacketNumber(protocol.Encryption1RTT).Return(protocol.PacketNumber(0x42))
+				sealingManager.EXPECT().Get1RTTSealer().Return(getSealer(), nil)
+				f := &wire.DatagramFrame{
+					DataLenPresent: true,
+					Data:           []byte("foobar"),
+				}
+				done := make(chan struct{})
+				go func() {
+					defer GinkgoRecover()
+					defer close(done)
+					datagramQueue.AddAndWait(f)
+				}()
+				// make sure the DATAGRAM has actually been queued
+				time.Sleep(scaleDuration(20 * time.Millisecond))
+
+				framer.EXPECT().HasData()
+				p, err := packer.PackPacket()
+				Expect(p).ToNot(BeNil())
+				Expect(err).ToNot(HaveOccurred())
+				Expect(p.frames).To(HaveLen(1))
+				Expect(p.frames[0].Frame).To(Equal(f))
+				Expect(p.buffer.Data).ToNot(BeEmpty())
+				Eventually(done).Should(BeClosed())
+			})
+
 			It("accounts for the space consumed by control frames", func() {
 				pnManager.EXPECT().PeekPacketNumber(protocol.Encryption1RTT).Return(protocol.PacketNumber(0x42), protocol.PacketNumberLen2)
 				sealingManager.EXPECT().Get1RTTSealer().Return(getSealer(), nil)
diff --git a/session.go b/session.go
index 7fc28c0c..24b165a1 100644
--- a/session.go
+++ b/session.go
@@ -204,6 +204,8 @@ type session struct {
 	keepAlivePingSent bool
 	keepAliveInterval time.Duration
 
+	datagramQueue *datagramQueue
+
 	logID  string
 	tracer logging.ConnectionTracer
 	logger utils.Logger
@@ -334,6 +336,7 @@ var newSession = func(
 		cs,
 		s.framer,
 		s.receivedPacketHandler,
+		s.datagramQueue,
 		s.perspective,
 		s.version,
 	)
@@ -454,6 +457,7 @@ var newClientSession = func(
 		cs,
 		s.framer,
 		s.receivedPacketHandler,
+		s.datagramQueue,
 		s.perspective,
 		s.version,
 	)
@@ -1307,6 +1311,9 @@ func (s *session) handleCloseError(closeErr closeError) {
 
 	s.streamsMap.CloseWithError(quicErr)
 	s.connIDManager.Close()
+	if s.datagramQueue != nil {
+		s.datagramQueue.CloseWithError(quicErr)
+	}
 
 	if s.tracer != nil {
 		// timeout errors are logged as soon as they occur (to distinguish between handshake and idle timeouts)