diff --git a/packet_packer.go b/packet_packer.go
index 27046816..9b2cccd5 100644
--- a/packet_packer.go
+++ b/packet_packer.go
@@ -457,11 +457,15 @@ func (p *packetPacker) getHeader(encLevel protocol.EncryptionLevel) *wire.Header
 	header := &wire.Header{
 		PacketNumber:    pnum,
 		PacketNumberLen: packetNumberLen,
+		Version:         p.version,
 	}
 
-	if p.version.UsesTLS() && encLevel != protocol.EncryptionForwardSecure {
+	if p.version.UsesIETFHeaderFormat() && encLevel != protocol.EncryptionForwardSecure {
 		header.IsLongHeader = true
 		header.SrcConnectionID = p.srcConnID
+		if !p.version.UsesVarintPacketNumbers() {
+			header.PacketNumberLen = protocol.PacketNumberLen4
+		}
 		// Set the payload len to maximum size.
 		// Since it is encoded as a varint, this guarantees us that the header will end up at most as big as GetLength() returns.
 		header.PayloadLen = p.maxPacketSize
@@ -478,15 +482,11 @@ func (p *packetPacker) getHeader(encLevel protocol.EncryptionLevel) *wire.Header
 	}
 	if !p.version.UsesTLS() {
 		if p.perspective == protocol.PerspectiveServer && encLevel == protocol.EncryptionSecure {
+			header.Type = protocol.PacketType0RTT
 			header.DiversificationNonce = p.divNonce
 		}
 		if p.perspective == protocol.PerspectiveClient && encLevel != protocol.EncryptionForwardSecure {
 			header.VersionFlag = true
-			header.Version = p.version
-		}
-	} else {
-		if encLevel != protocol.EncryptionForwardSecure {
-			header.Version = p.version
 		}
 	}
 	return header
diff --git a/packet_packer_test.go b/packet_packer_test.go
index c9d71f5e..ae40aa2e 100644
--- a/packet_packer_test.go
+++ b/packet_packer_test.go
@@ -103,6 +103,7 @@ var _ = Describe("Packet packer", func() {
 
 	Context("determining the maximum packet size", func() {
 		connID := protocol.ConnectionID{1, 2, 3, 4, 5, 6, 7, 8}
+
 		It("uses the minimum initial size, if it can't determine if the remote address is IPv4 or IPv6", func() {
 			remoteAddr := &net.TCPAddr{}
 			packer = newPacketPacker(connID, connID, 1, nil, remoteAddr, nil, nil, nil, nil, protocol.PerspectiveServer, protocol.VersionWhatever)
@@ -176,6 +177,7 @@ var _ = Describe("Packet packer", func() {
 			})
 
 			It("it omits the connection ID for forward-secure packets", func() {
+				packer.version = protocol.Version43
 				ph := packer.getHeader(protocol.EncryptionForwardSecure)
 				Expect(ph.DestConnectionID.Len()).ToNot(BeZero())
 				packer.SetOmitConnectionID()
@@ -225,6 +227,52 @@ var _ = Describe("Packet packer", func() {
 			})
 		})
 
+		Context("Header (for gQUIC 44)", func() {
+			BeforeEach(func() {
+				packer.version = protocol.Version44
+			})
+
+			It("sends an Initial packet as the first packets, for the client", func() {
+				packer.perspective = protocol.PerspectiveClient
+				packer.hasSentPacket = false
+				h := packer.getHeader(protocol.EncryptionUnencrypted)
+				Expect(h.IsLongHeader).To(BeTrue())
+				Expect(h.Type).To(Equal(protocol.PacketTypeInitial))
+				Expect(h.Version).To(Equal(protocol.Version44))
+				Expect(h.DestConnectionID).To(Equal(packer.destConnID))
+				Expect(h.SrcConnectionID).To(Equal(packer.srcConnID))
+				Expect(h.PacketNumberLen).To(Equal(protocol.PacketNumberLen4))
+			})
+
+			It("sends a Handshake for non-forward-secure packets, for the server", func() {
+				packer.perspective = protocol.PerspectiveServer
+				h := packer.getHeader(protocol.EncryptionUnencrypted)
+				Expect(h.IsLongHeader).To(BeTrue())
+				Expect(h.Type).To(Equal(protocol.PacketTypeHandshake))
+				Expect(h.Version).To(Equal(protocol.Version44))
+				Expect(h.DestConnectionID).To(Equal(packer.destConnID))
+				Expect(h.SrcConnectionID).To(Equal(packer.srcConnID))
+				Expect(h.PacketNumberLen).To(Equal(protocol.PacketNumberLen4))
+			})
+
+			It("sets the Diversification Nonce for secure packets", func() {
+				packer.perspective = protocol.PerspectiveServer
+				Expect(divNonce).ToNot(BeEmpty())
+				h := packer.getHeader(protocol.EncryptionSecure)
+				Expect(h.IsLongHeader).To(BeTrue())
+				Expect(h.Version).To(Equal(protocol.Version44))
+				Expect(h.Type).To(Equal(protocol.PacketType0RTT))
+				Expect(h.DiversificationNonce).To(Equal(divNonce))
+			})
+
+			It("uses the Short Header for forward-secure packets", func() {
+				h := packer.getHeader(protocol.EncryptionForwardSecure)
+				Expect(h.IsLongHeader).To(BeFalse())
+				Expect(h.IsPublicHeader).To(BeFalse())
+				Expect(h.DestConnectionID).To(Equal(packer.destConnID))
+			})
+		})
+
 		Context("Header (for IETF draft QUIC)", func() {
 			BeforeEach(func() {
 				packer.version = versionIETFHeader