diff --git a/pkg/sentry/fs/host/socket.go b/pkg/sentry/fs/host/socket.go
index 44c4ee5f2..2392787cb 100644
--- a/pkg/sentry/fs/host/socket.go
+++ b/pkg/sentry/fs/host/socket.go
@@ -65,7 +65,7 @@ type ConnectedEndpoint struct {
 	// GetSockOpt and message splitting/rejection in SendMsg, but do not
 	// prevent lots of small messages from filling the real send buffer
 	// size on the host.
-	sndbuf int `state:"nosave"`
+	sndbuf int64 `state:"nosave"`
 
 	// mu protects the fields below.
 	mu sync.RWMutex `state:"nosave"`
@@ -107,7 +107,7 @@ func (c *ConnectedEndpoint) init() *syserr.Error {
 	}
 
 	c.stype = linux.SockType(stype)
-	c.sndbuf = sndbuf
+	c.sndbuf = int64(sndbuf)
 
 	return nil
 }
@@ -202,7 +202,7 @@ func newSocket(ctx context.Context, orgfd int, saveable bool) (*fs.File, error)
 }
 
 // Send implements transport.ConnectedEndpoint.Send.
-func (c *ConnectedEndpoint) Send(data [][]byte, controlMessages transport.ControlMessages, from tcpip.FullAddress) (uintptr, bool, *syserr.Error) {
+func (c *ConnectedEndpoint) Send(data [][]byte, controlMessages transport.ControlMessages, from tcpip.FullAddress) (int64, bool, *syserr.Error) {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
@@ -279,7 +279,7 @@ func (c *ConnectedEndpoint) EventUpdate() {
 }
 
 // Recv implements transport.Receiver.Recv.
-func (c *ConnectedEndpoint) Recv(data [][]byte, creds bool, numRights uintptr, peek bool) (uintptr, uintptr, transport.ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
+func (c *ConnectedEndpoint) Recv(data [][]byte, creds bool, numRights int, peek bool) (int64, int64, transport.ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
diff --git a/pkg/sentry/fs/host/socket_iovec.go b/pkg/sentry/fs/host/socket_iovec.go
index 05d7c79ad..af6955675 100644
--- a/pkg/sentry/fs/host/socket_iovec.go
+++ b/pkg/sentry/fs/host/socket_iovec.go
@@ -55,19 +55,19 @@ func copyFromMulti(dst []byte, src [][]byte) {
 //
 // If intermediate != nil, iovecs references intermediate rather than bufs and
 // the caller must copy to/from bufs as necessary.
-func buildIovec(bufs [][]byte, maxlen int, truncate bool) (length uintptr, iovecs []syscall.Iovec, intermediate []byte, err error) {
+func buildIovec(bufs [][]byte, maxlen int64, truncate bool) (length int64, iovecs []syscall.Iovec, intermediate []byte, err error) {
 	var iovsRequired int
 	for _, b := range bufs {
-		length += uintptr(len(b))
+		length += int64(len(b))
 		if len(b) > 0 {
 			iovsRequired++
 		}
 	}
 
 	stopLen := length
-	if length > uintptr(maxlen) {
+	if length > maxlen {
 		if truncate {
-			stopLen = uintptr(maxlen)
+			stopLen = maxlen
 			err = syserror.EAGAIN
 		} else {
 			return 0, nil, nil, syserror.EMSGSIZE
@@ -85,7 +85,7 @@ func buildIovec(bufs [][]byte, maxlen int, truncate bool) (length uintptr, iovec
 		}}, b, err
 	}
 
-	var total uintptr
+	var total int64
 	iovecs = make([]syscall.Iovec, 0, iovsRequired)
 	for i := range bufs {
 		l := len(bufs[i])
@@ -93,9 +93,9 @@ func buildIovec(bufs [][]byte, maxlen int, truncate bool) (length uintptr, iovec
 			continue
 		}
 
-		stop := l
-		if total+uintptr(stop) > stopLen {
-			stop = int(stopLen - total)
+		stop := int64(l)
+		if total+stop > stopLen {
+			stop = stopLen - total
 		}
 
 		iovecs = append(iovecs, syscall.Iovec{
@@ -103,7 +103,7 @@ func buildIovec(bufs [][]byte, maxlen int, truncate bool) (length uintptr, iovec
 			Len:  uint64(stop),
 		})
 
-		total += uintptr(stop)
+		total += stop
 		if total >= stopLen {
 			break
 		}
diff --git a/pkg/sentry/fs/host/socket_unsafe.go b/pkg/sentry/fs/host/socket_unsafe.go
index e57be0506..f3bbed7ea 100644
--- a/pkg/sentry/fs/host/socket_unsafe.go
+++ b/pkg/sentry/fs/host/socket_unsafe.go
@@ -23,7 +23,7 @@ import (
 //
 // If the total length of bufs is > maxlen, fdReadVec will do a partial read
 // and err will indicate why the message was truncated.
-func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int) (readLen uintptr, msgLen uintptr, controlLen uint64, controlTrunc bool, err error) {
+func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int64) (readLen int64, msgLen int64, controlLen uint64, controlTrunc bool, err error) {
 	flags := uintptr(syscall.MSG_DONTWAIT | syscall.MSG_TRUNC)
 	if peek {
 		flags |= syscall.MSG_PEEK
@@ -48,11 +48,12 @@ func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int) (re
 		msg.Iovlen = uint64(len(iovecs))
 	}
 
-	n, _, e := syscall.RawSyscall(syscall.SYS_RECVMSG, uintptr(fd), uintptr(unsafe.Pointer(&msg)), flags)
+	rawN, _, e := syscall.RawSyscall(syscall.SYS_RECVMSG, uintptr(fd), uintptr(unsafe.Pointer(&msg)), flags)
 	if e != 0 {
 		// N.B. prioritize the syscall error over the buildIovec error.
 		return 0, 0, 0, false, e
 	}
+	n := int64(rawN)
 
 	// Copy data back to bufs.
 	if intermediate != nil {
@@ -72,7 +73,7 @@ func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int) (re
 //
 // If the total length of bufs is > maxlen && truncate, fdWriteVec will do a
 // partial write and err will indicate why the message was truncated.
-func fdWriteVec(fd int, bufs [][]byte, maxlen int, truncate bool) (uintptr, uintptr, error) {
+func fdWriteVec(fd int, bufs [][]byte, maxlen int64, truncate bool) (int64, int64, error) {
 	length, iovecs, intermediate, err := buildIovec(bufs, maxlen, truncate)
 	if err != nil && len(iovecs) == 0 {
 		// No partial write to do, return error immediately.
@@ -96,5 +97,5 @@ func fdWriteVec(fd int, bufs [][]byte, maxlen int, truncate bool) (uintptr, uint
 		return 0, length, e
 	}
 
-	return n, length, err
+	return int64(n), length, err
 }
diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go
index 0f2cd05fc..4d8a5ac22 100644
--- a/pkg/sentry/socket/epsocket/epsocket.go
+++ b/pkg/sentry/socket/epsocket/epsocket.go
@@ -2046,7 +2046,7 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 		n, _, err = s.Endpoint.Write(v, opts)
 	}
 	dontWait := flags&linux.MSG_DONTWAIT != 0
-	if err == nil && (n >= uintptr(v.Size()) || dontWait) {
+	if err == nil && (n >= int64(v.Size()) || dontWait) {
 		// Complete write.
 		return int(n), nil
 	}
diff --git a/pkg/sentry/socket/unix/io.go b/pkg/sentry/socket/unix/io.go
index 760c7beab..2ec1a662d 100644
--- a/pkg/sentry/socket/unix/io.go
+++ b/pkg/sentry/socket/unix/io.go
@@ -62,7 +62,7 @@ type EndpointReader struct {
 	Creds bool
 
 	// NumRights is the number of SCM_RIGHTS FDs requested.
-	NumRights uintptr
+	NumRights int
 
 	// Peek indicates that the data should not be consumed from the
 	// endpoint.
@@ -70,7 +70,7 @@ type EndpointReader struct {
 
 	// MsgSize is the size of the message that was read from. For stream
 	// sockets, it is the amount read.
-	MsgSize uintptr
+	MsgSize int64
 
 	// From, if not nil, will be set with the address read from.
 	From *tcpip.FullAddress
diff --git a/pkg/sentry/socket/unix/transport/connectioned.go b/pkg/sentry/socket/unix/transport/connectioned.go
index 73d2df15d..4bd15808a 100644
--- a/pkg/sentry/socket/unix/transport/connectioned.go
+++ b/pkg/sentry/socket/unix/transport/connectioned.go
@@ -436,7 +436,7 @@ func (e *connectionedEndpoint) Bind(addr tcpip.FullAddress, commit func() *syser
 
 // SendMsg writes data and a control message to the endpoint's peer.
 // This method does not block if the data cannot be written.
-func (e *connectionedEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (uintptr, *syserr.Error) {
+func (e *connectionedEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (int64, *syserr.Error) {
 	// Stream sockets do not support specifying the endpoint. Seqpacket
 	// sockets ignore the passed endpoint.
 	if e.stype == linux.SOCK_STREAM && to != nil {
diff --git a/pkg/sentry/socket/unix/transport/connectionless.go b/pkg/sentry/socket/unix/transport/connectionless.go
index c7f7c5b16..0322dec0b 100644
--- a/pkg/sentry/socket/unix/transport/connectionless.go
+++ b/pkg/sentry/socket/unix/transport/connectionless.go
@@ -99,7 +99,7 @@ func (e *connectionlessEndpoint) UnidirectionalConnect(ctx context.Context) (Con
 
 // SendMsg writes data and a control message to the specified endpoint.
 // This method does not block if the data cannot be written.
-func (e *connectionlessEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (uintptr, *syserr.Error) {
+func (e *connectionlessEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (int64, *syserr.Error) {
 	if to == nil {
 		return e.baseEndpoint.SendMsg(ctx, data, c, nil)
 	}
diff --git a/pkg/sentry/socket/unix/transport/unix.go b/pkg/sentry/socket/unix/transport/unix.go
index 7fb9cb1e0..2b0ad6395 100644
--- a/pkg/sentry/socket/unix/transport/unix.go
+++ b/pkg/sentry/socket/unix/transport/unix.go
@@ -121,13 +121,13 @@ type Endpoint interface {
 	// CMTruncated indicates that the numRights hint was used to receive fewer
 	// than the total available SCM_RIGHTS FDs. Additional truncation may be
 	// required by the caller.
-	RecvMsg(ctx context.Context, data [][]byte, creds bool, numRights uintptr, peek bool, addr *tcpip.FullAddress) (recvLen, msgLen uintptr, cm ControlMessages, CMTruncated bool, err *syserr.Error)
+	RecvMsg(ctx context.Context, data [][]byte, creds bool, numRights int, peek bool, addr *tcpip.FullAddress) (recvLen, msgLen int64, cm ControlMessages, CMTruncated bool, err *syserr.Error)
 
 	// SendMsg writes data and a control message to the endpoint's peer.
 	// This method does not block if the data cannot be written.
 	//
 	// SendMsg does not take ownership of any of its arguments on error.
-	SendMsg(context.Context, [][]byte, ControlMessages, BoundEndpoint) (uintptr, *syserr.Error)
+	SendMsg(context.Context, [][]byte, ControlMessages, BoundEndpoint) (int64, *syserr.Error)
 
 	// Connect connects this endpoint directly to another.
 	//
@@ -291,7 +291,7 @@ type Receiver interface {
 	// See Endpoint.RecvMsg for documentation on shared arguments.
 	//
 	// notify indicates if RecvNotify should be called.
-	Recv(data [][]byte, creds bool, numRights uintptr, peek bool) (recvLen, msgLen uintptr, cm ControlMessages, CMTruncated bool, source tcpip.FullAddress, notify bool, err *syserr.Error)
+	Recv(data [][]byte, creds bool, numRights int, peek bool) (recvLen, msgLen int64, cm ControlMessages, CMTruncated bool, source tcpip.FullAddress, notify bool, err *syserr.Error)
 
 	// RecvNotify notifies the Receiver of a successful Recv. This must not be
 	// called while holding any endpoint locks.
@@ -331,7 +331,7 @@ type queueReceiver struct {
 }
 
 // Recv implements Receiver.Recv.
-func (q *queueReceiver) Recv(data [][]byte, creds bool, numRights uintptr, peek bool) (uintptr, uintptr, ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
+func (q *queueReceiver) Recv(data [][]byte, creds bool, numRights int, peek bool) (int64, int64, ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
 	var m *message
 	var notify bool
 	var err *syserr.Error
@@ -344,13 +344,13 @@ func (q *queueReceiver) Recv(data [][]byte, creds bool, numRights uintptr, peek
 		return 0, 0, ControlMessages{}, false, tcpip.FullAddress{}, false, err
 	}
 	src := []byte(m.Data)
-	var copied uintptr
+	var copied int64
 	for i := 0; i < len(data) && len(src) > 0; i++ {
 		n := copy(data[i], src)
-		copied += uintptr(n)
+		copied += int64(n)
 		src = src[n:]
 	}
-	return copied, uintptr(len(m.Data)), m.Control, false, m.Address, notify, nil
+	return copied, int64(len(m.Data)), m.Control, false, m.Address, notify, nil
 }
 
 // RecvNotify implements Receiver.RecvNotify.
@@ -401,11 +401,11 @@ type streamQueueReceiver struct {
 	addr    tcpip.FullAddress
 }
 
-func vecCopy(data [][]byte, buf []byte) (uintptr, [][]byte, []byte) {
-	var copied uintptr
+func vecCopy(data [][]byte, buf []byte) (int64, [][]byte, []byte) {
+	var copied int64
 	for len(data) > 0 && len(buf) > 0 {
 		n := copy(data[0], buf)
-		copied += uintptr(n)
+		copied += int64(n)
 		buf = buf[n:]
 		data[0] = data[0][n:]
 		if len(data[0]) == 0 {
@@ -443,7 +443,7 @@ func (q *streamQueueReceiver) RecvMaxQueueSize() int64 {
 }
 
 // Recv implements Receiver.Recv.
-func (q *streamQueueReceiver) Recv(data [][]byte, wantCreds bool, numRights uintptr, peek bool) (uintptr, uintptr, ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
+func (q *streamQueueReceiver) Recv(data [][]byte, wantCreds bool, numRights int, peek bool) (int64, int64, ControlMessages, bool, tcpip.FullAddress, bool, *syserr.Error) {
 	q.mu.Lock()
 	defer q.mu.Unlock()
 
@@ -464,7 +464,7 @@ func (q *streamQueueReceiver) Recv(data [][]byte, wantCreds bool, numRights uint
 		q.addr = m.Address
 	}
 
-	var copied uintptr
+	var copied int64
 	if peek {
 		// Don't consume control message if we are peeking.
 		c := q.control.Clone()
@@ -531,7 +531,7 @@ func (q *streamQueueReceiver) Recv(data [][]byte, wantCreds bool, numRights uint
 			break
 		}
 
-		var cpd uintptr
+		var cpd int64
 		cpd, data, q.buffer = vecCopy(data, q.buffer)
 		copied += cpd
 
@@ -569,7 +569,7 @@ type ConnectedEndpoint interface {
 	//
 	// syserr.ErrWouldBlock can be returned along with a partial write if
 	// the caller should block to send the rest of the data.
-	Send(data [][]byte, controlMessages ControlMessages, from tcpip.FullAddress) (n uintptr, notify bool, err *syserr.Error)
+	Send(data [][]byte, controlMessages ControlMessages, from tcpip.FullAddress) (n int64, notify bool, err *syserr.Error)
 
 	// SendNotify notifies the ConnectedEndpoint of a successful Send. This
 	// must not be called while holding any endpoint locks.
@@ -637,7 +637,7 @@ func (e *connectedEndpoint) GetLocalAddress() (tcpip.FullAddress, *tcpip.Error)
 }
 
 // Send implements ConnectedEndpoint.Send.
-func (e *connectedEndpoint) Send(data [][]byte, controlMessages ControlMessages, from tcpip.FullAddress) (uintptr, bool, *syserr.Error) {
+func (e *connectedEndpoint) Send(data [][]byte, controlMessages ControlMessages, from tcpip.FullAddress) (int64, bool, *syserr.Error) {
 	var l int64
 	for _, d := range data {
 		l += int64(len(d))
@@ -665,7 +665,7 @@ func (e *connectedEndpoint) Send(data [][]byte, controlMessages ControlMessages,
 	}
 
 	l, notify, err := e.writeQueue.Enqueue(&message{Data: buffer.View(v), Control: controlMessages, Address: from}, truncate)
-	return uintptr(l), notify, err
+	return int64(l), notify, err
 }
 
 // SendNotify implements ConnectedEndpoint.SendNotify.
@@ -781,7 +781,7 @@ func (e *baseEndpoint) Connected() bool {
 }
 
 // RecvMsg reads data and a control message from the endpoint.
-func (e *baseEndpoint) RecvMsg(ctx context.Context, data [][]byte, creds bool, numRights uintptr, peek bool, addr *tcpip.FullAddress) (uintptr, uintptr, ControlMessages, bool, *syserr.Error) {
+func (e *baseEndpoint) RecvMsg(ctx context.Context, data [][]byte, creds bool, numRights int, peek bool, addr *tcpip.FullAddress) (int64, int64, ControlMessages, bool, *syserr.Error) {
 	e.Lock()
 
 	if e.receiver == nil {
@@ -807,7 +807,7 @@ func (e *baseEndpoint) RecvMsg(ctx context.Context, data [][]byte, creds bool, n
 
 // SendMsg writes data and a control message to the endpoint's peer.
 // This method does not block if the data cannot be written.
-func (e *baseEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (uintptr, *syserr.Error) {
+func (e *baseEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMessages, to BoundEndpoint) (int64, *syserr.Error) {
 	e.Lock()
 	if !e.Connected() {
 		e.Unlock()
diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go
index 9032b7580..8a3f65236 100644
--- a/pkg/sentry/socket/unix/unix.go
+++ b/pkg/sentry/socket/unix/unix.go
@@ -535,7 +535,7 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 		Ctx:       t,
 		Endpoint:  s.ep,
 		Creds:     wantCreds,
-		NumRights: uintptr(numRights),
+		NumRights: numRights,
 		Peek:      peek,
 	}
 	if senderRequested {
diff --git a/pkg/tcpip/adapters/gonet/gonet.go b/pkg/tcpip/adapters/gonet/gonet.go
index f8c7cf3c5..cd6ce930a 100644
--- a/pkg/tcpip/adapters/gonet/gonet.go
+++ b/pkg/tcpip/adapters/gonet/gonet.go
@@ -404,7 +404,7 @@ func (c *Conn) Write(b []byte) (int, error) {
 			}
 		}
 
-		var n uintptr
+		var n int64
 		var resCh <-chan struct{}
 		n, resCh, err = c.ep.Write(tcpip.SlicePayload(v), tcpip.WriteOptions{})
 		nbytes += int(n)
diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go
index eee3144cd..8146e8444 100644
--- a/pkg/tcpip/stack/transport_test.go
+++ b/pkg/tcpip/stack/transport_test.go
@@ -65,7 +65,7 @@ func (*fakeTransportEndpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.Contr
 	return buffer.View{}, tcpip.ControlMessages{}, nil
 }
 
-func (f *fakeTransportEndpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (f *fakeTransportEndpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
 	if len(f.route.RemoteAddress) == 0 {
 		return 0, nil, tcpip.ErrNoRoute
 	}
@@ -79,10 +79,10 @@ func (f *fakeTransportEndpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions)
 		return 0, nil, err
 	}
 
-	return uintptr(len(v)), nil, nil
+	return int64(len(v)), nil, nil
 }
 
-func (f *fakeTransportEndpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+func (f *fakeTransportEndpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	return 0, tcpip.ControlMessages{}, nil
 }
 
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index db6d5a9bf..f664673b3 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -329,12 +329,12 @@ type Endpoint interface {
 	// ErrNoLinkAddress and a notification channel is returned for the caller to
 	// block. Channel is closed once address resolution is complete (success or
 	// not). The channel is only non-nil in this case.
-	Write(Payload, WriteOptions) (uintptr, <-chan struct{}, *Error)
+	Write(Payload, WriteOptions) (int64, <-chan struct{}, *Error)
 
 	// Peek reads data without consuming it from the endpoint.
 	//
 	// This method does not block if there is no data pending.
-	Peek([][]byte) (uintptr, ControlMessages, *Error)
+	Peek([][]byte) (int64, ControlMessages, *Error)
 
 	// Connect connects the endpoint to its peer. Specifying a NIC is
 	// optional.
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 9a4306011..5ca208619 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -233,7 +233,7 @@ func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err *tcpi
 
 // Write writes data to the endpoint's peer. This method does not block
 // if the data cannot be written.
-func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
 	// MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.)
 	if opts.More {
 		return 0, nil, tcpip.ErrInvalidOptionValue
@@ -335,11 +335,11 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-c
 		return 0, nil, err
 	}
 
-	return uintptr(len(v)), nil, nil
+	return int64(len(v)), nil, nil
 }
 
 // Peek only returns data from a single datagram, so do nothing here.
-func (e *endpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+func (e *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	return 0, tcpip.ControlMessages{}, nil
 }
 
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index eab3dcbd2..cde655bb6 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -232,7 +232,7 @@ func (ep *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMes
 }
 
 // Write implements tcpip.Endpoint.Write.
-func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
 	// MSG_MORE is unimplemented. This also means that MSG_EOR is a no-op.
 	if opts.More {
 		return 0, nil, tcpip.ErrInvalidOptionValue
@@ -336,7 +336,7 @@ func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (uintp
 
 // finishWrite writes the payload to a route. It resolves the route if
 // necessary. It's really just a helper to make defer unnecessary in Write.
-func (ep *endpoint) finishWrite(payloadBytes []byte, route *stack.Route) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (ep *endpoint) finishWrite(payloadBytes []byte, route *stack.Route) (int64, <-chan struct{}, *tcpip.Error) {
 	// We may need to resolve the route (match a link layer address to the
 	// network address). If that requires blocking (e.g. to use ARP),
 	// return a channel on which the caller can wait.
@@ -366,11 +366,11 @@ func (ep *endpoint) finishWrite(payloadBytes []byte, route *stack.Route) (uintpt
 		return 0, nil, tcpip.ErrUnknownProtocol
 	}
 
-	return uintptr(len(payloadBytes)), nil, nil
+	return int64(len(payloadBytes)), nil, nil
 }
 
 // Peek implements tcpip.Endpoint.Peek.
-func (ep *endpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+func (ep *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	return 0, tcpip.ControlMessages{}, nil
 }
 
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 7c42a830a..ed23ea0b8 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -907,7 +907,7 @@ func (e *endpoint) isEndpointWritableLocked() (int, *tcpip.Error) {
 }
 
 // Write writes data to the endpoint's peer.
-func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
 	// Linux completely ignores any address passed to sendto(2) for TCP sockets
 	// (without the MSG_FASTOPEN flag). Corking is unimplemented, so opts.More
 	// and opts.EndOfRecord are also ignored.
@@ -976,13 +976,13 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-c
 		// Let the protocol goroutine do the work.
 		e.sndWaker.Assert()
 	}
-	return uintptr(l), nil, nil
+	return int64(l), nil, nil
 }
 
 // Peek reads data without consuming it from the endpoint.
 //
 // This method does not block if there is no data pending.
-func (e *endpoint) Peek(vec [][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	e.mu.RLock()
 	defer e.mu.RUnlock()
 
@@ -1008,8 +1008,7 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Er
 	// Make a copy of vec so we can modify the slide headers.
 	vec = append([][]byte(nil), vec...)
 
-	var num uintptr
-
+	var num int64
 	for s := e.rcvList.Front(); s != nil; s = s.Next() {
 		views := s.data.Views()
 
@@ -1028,7 +1027,7 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Er
 				n := copy(vec[0], v)
 				v = v[n:]
 				vec[0] = vec[0][n:]
-				num += uintptr(n)
+				num += int64(n)
 			}
 		}
 	}
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 7c12a6092..c50f5abb3 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -315,7 +315,7 @@ func (e *endpoint) connectRoute(nicid tcpip.NICID, addr tcpip.FullAddress, netPr
 
 // Write writes data to the endpoint's peer. This method does not block
 // if the data cannot be written.
-func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-chan struct{}, *tcpip.Error) {
+func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
 	// MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.)
 	if opts.More {
 		return 0, nil, tcpip.ErrInvalidOptionValue
@@ -421,11 +421,11 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-c
 	if err := sendUDP(route, buffer.View(v).ToVectorisedView(), e.id.LocalPort, dstPort, ttl); err != nil {
 		return 0, nil, err
 	}
-	return uintptr(len(v)), nil, nil
+	return int64(len(v)), nil, nil
 }
 
 // Peek only returns data from a single datagram, so do nothing here.
-func (e *endpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+func (e *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	return 0, tcpip.ControlMessages{}, nil
 }
 
diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go
index 56c285f88..26c3241e3 100644
--- a/pkg/tcpip/transport/udp/udp_test.go
+++ b/pkg/tcpip/transport/udp/udp_test.go
@@ -567,7 +567,7 @@ func testV4Write(c *testContext) uint16 {
 	if err != nil {
 		c.t.Fatalf("Write failed: %v", err)
 	}
-	if n != uintptr(len(payload)) {
+	if n != int64(len(payload)) {
 		c.t.Fatalf("Bad number of bytes written: got %v, want %v", n, len(payload))
 	}
 
@@ -597,7 +597,7 @@ func testV6Write(c *testContext) uint16 {
 	if err != nil {
 		c.t.Fatalf("Write failed: %v", err)
 	}
-	if n != uintptr(len(payload)) {
+	if n != int64(len(payload)) {
 		c.t.Fatalf("Bad number of bytes written: got %v, want %v", n, len(payload))
 	}
 
@@ -754,7 +754,7 @@ func TestV6WriteOnConnected(t *testing.T) {
 	if err != nil {
 		c.t.Fatalf("Write failed: %v", err)
 	}
-	if n != uintptr(len(payload)) {
+	if n != int64(len(payload)) {
 		c.t.Fatalf("Bad number of bytes written: got %v, want %v", n, len(payload))
 	}
 
@@ -790,7 +790,7 @@ func TestV4WriteOnConnected(t *testing.T) {
 	if err != nil {
 		c.t.Fatalf("Write failed: %v", err)
 	}
-	if n != uintptr(len(payload)) {
+	if n != int64(len(payload)) {
 		c.t.Fatalf("Bad number of bytes written: got %v, want %v", n, len(payload))
 	}
 
@@ -948,7 +948,7 @@ func TestTTL(t *testing.T) {
 				if err != nil {
 					c.t.Fatalf("Write failed: %v", err)
 				}
-				if n != uintptr(len(payload)) {
+				if n != int64(len(payload)) {
 					c.t.Fatalf("got c.ep.Write(...) = %d, want = %d", n, len(payload))
 				}