diff --git a/client.go b/client.go
index e8d4a91..3d0acf3 100644
--- a/client.go
+++ b/client.go
@@ -82,7 +82,7 @@ func (c Client) Put(filename string, mode string, handler func(w *io.PipeWriter)
 		handler(writer)
 		wg.Done()
 	}()
-	s.Run(false)
+	s.run(false)
 	wg.Wait()
 	return nil
 }
@@ -105,7 +105,7 @@ func (c Client) Get(filename string, mode string, handler func(r *io.PipeReader)
 		handler(reader)
 		wg.Done()
 	}()
-	r.Run(false)
+	r.run(false)
 	wg.Wait()
 	return fmt.Errorf("Send timeout")
 }
diff --git a/packet.go b/packet.go
index 478019b..29d1fa2 100644
--- a/packet.go
+++ b/packet.go
@@ -153,7 +153,7 @@ func (p *ERROR) Pack() []byte {
 	return buffer.Bytes()
 }
 
-func ParsePacket(data []byte) (*Packet, error) {
+func ParsePacket(data []byte) (Packet, error) {
 	var p Packet
 	opcode := binary.BigEndian.Uint16(data)
 	switch opcode {
@@ -168,8 +168,7 @@ func ParsePacket(data []byte) (*Packet, error) {
 	case OP_ERROR:
 		p = &ERROR{}
 	default:
-		return nil, fmt.Errorf("Unknown packet type: %d", opcode)
+		return nil, fmt.Errorf("unknown opcode: %d", opcode)
 	}
-	pp := Packet(p)
-	return &pp, pp.Unpack(data)
+	return p, p.Unpack(data)
 }
diff --git a/receiver.go b/receiver.go
index adb83b3..821b8a8 100644
--- a/receiver.go
+++ b/receiver.go
@@ -1,6 +1,7 @@
 package tftp
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -17,14 +18,16 @@ type receiver struct {
 	log        *log.Logger
 }
 
-func (r *receiver) Run(isServerMode bool) error {
+var ErrReceiveTimeout = errors.New("receive timeout")
+
+func (r *receiver) run(serverMode bool) error {
 	var blockNumber uint16
 	blockNumber = 1
 	var buffer []byte
 	buffer = make([]byte, MAX_DATAGRAM_SIZE)
 	firstBlock := true
 	for {
-		last, e := r.receiveBlock(buffer, blockNumber, firstBlock && !isServerMode)
+		last, e := r.receiveBlock(buffer, blockNumber, firstBlock && !serverMode)
 		if e != nil {
 			if r.log != nil {
 				r.log.Printf("Error receiving block %d: %v", blockNumber, e)
@@ -69,7 +72,7 @@ func (r *receiver) receiveBlock(b []byte, n uint16, firstBlockOnClient bool) (la
 			if e != nil {
 				continue
 			}
-			switch p := Packet(*packet).(type) {
+			switch p := packet.(type) {
 			case *DATA:
 				r.log.Printf("got DATA #%d (%d bytes)", p.BlockNumber, len(p.Data))
 				if n == p.BlockNumber {
@@ -90,7 +93,7 @@ func (r *receiver) receiveBlock(b []byte, n uint16, firstBlockOnClient bool) (la
 			}
 		}
 	}
-	return false, fmt.Errorf("Receive timeout")
+	return false, ErrReceiveTimeout
 }
 
 func (r *receiver) terminate(b []byte, n uint16, dallying bool) (e error) {
@@ -117,7 +120,7 @@ func (r *receiver) terminate(b []byte, n uint16, dallying bool) (e error) {
 			if e != nil {
 				continue
 			}
-			switch p := Packet(*packet).(type) {
+			switch p := packet.(type) {
 			case *DATA:
 				r.log.Printf("got DATA #%d (%d bytes)", p.BlockNumber, len(p.Data))
 				if n == p.BlockNumber {
diff --git a/sender.go b/sender.go
index 92bb056..850daa7 100644
--- a/sender.go
+++ b/sender.go
@@ -1,6 +1,7 @@
 package tftp
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -17,15 +18,17 @@ type sender struct {
 	log        *log.Logger
 }
 
-func (s *sender) Run(isServerMode bool) {
+var ErrSendTimeout = errors.New("send timeout")
+
+func (s *sender) run(serverMode bool) {
 	var buffer, tmp []byte
 	buffer = make([]byte, BLOCK_SIZE)
 	tmp = make([]byte, MAX_DATAGRAM_SIZE)
-	if !isServerMode {
-		e := s.sendRequest(tmp)
-		if e != nil {
-			s.log.Printf("Error starting transmission: %v", e)
-			s.reader.CloseWithError(e)
+	if !serverMode {
+		err := s.sendRequest(tmp)
+		if err != nil {
+			s.log.Printf("Error starting transmission: %v", err)
+			s.reader.CloseWithError(err)
 			return
 		}
 	}
@@ -93,7 +96,7 @@ func (s *sender) sendRequest(tmp []byte) (e error) {
 			if e != nil {
 				continue
 			}
-			switch p := Packet(*packet).(type) {
+			switch p := packet.(type) {
 			case *ACK:
 				if p.BlockNumber == 0 {
 					s.log.Printf("got ACK #0")
@@ -105,7 +108,7 @@ func (s *sender) sendRequest(tmp []byte) (e error) {
 			}
 		}
 	}
-	return fmt.Errorf("Send timeout")
+	return ErrSendTimeout
 }
 
 func (s *sender) sendBlock(b []byte, c int, n uint16, tmp []byte) (e error) {
@@ -128,7 +131,7 @@ func (s *sender) sendBlock(b []byte, c int, n uint16, tmp []byte) (e error) {
 			if e != nil {
 				continue
 			}
-			switch p := Packet(*packet).(type) {
+			switch p := packet.(type) {
 			case *ACK:
 				s.log.Printf("got ACK #%d", p.BlockNumber)
 				if n == p.BlockNumber {
@@ -139,5 +142,5 @@ func (s *sender) sendBlock(b []byte, c int, n uint16, tmp []byte) (e error) {
 			}
 		}
 	}
-	return fmt.Errorf("Send timeout")
+	return ErrSendTimeout
 }
diff --git a/server.go b/server.go
index d78e102..bc9805c 100644
--- a/server.go
+++ b/server.go
@@ -82,7 +82,7 @@ func (s Server) processRequest(conn *net.UDPConn) error {
 	if e != nil {
 		return nil
 	}
-	switch p := Packet(*p).(type) {
+	switch p := p.(type) {
 	case *WRQ:
 		s.Log.Printf("got WRQ (filename=%s, mode=%s)", p.Filename, p.Mode)
 		trasnmissionConn, e := s.transmissionConn()
@@ -102,7 +102,7 @@ func (s Server) processRequest(conn *net.UDPConn) error {
 			s.Log.Printf("sent ERROR (code=%d): %s", 1, e.Error())
 			return e
 		}
-		go r.Run(true)
+		go r.run(true)
 	case *RRQ:
 		s.Log.Printf("got RRQ (filename=%s, mode=%s)", p.Filename, p.Mode)
 		trasnmissionConn, e := s.transmissionConn()
@@ -112,7 +112,7 @@ func (s Server) processRequest(conn *net.UDPConn) error {
 		reader, writer := io.Pipe()
 		r := &sender{remoteAddr, trasnmissionConn, reader, p.Filename, p.Mode, s.Log}
 		go s.WriteHandler(p.Filename, writer)
-		go r.Run(true)
+		go r.run(true)
 	}
 	return nil
 }
diff --git a/tftp_test.go b/tftp_test.go
index 839c11f..a266c99 100644
--- a/tftp_test.go
+++ b/tftp_test.go
@@ -57,6 +57,55 @@ func TestPutGet(t *testing.T) {
 	}
 }
 
+func TestTimeout(t *testing.T) {
+	addr, _ := net.ResolveUDPAddr("udp", "localhost:12322")
+
+	log := log.New(os.Stderr, "", log.Ldate|log.Ltime)
+
+	writeHandler := func(filename string, r *io.PipeReader) {
+		buf := make([]byte, 64)
+		for i := 0; i < 5; i++ {
+			_, err := r.Read(buf)
+			if err != nil {
+				panic(err)
+			}
+		}
+		// server "fail" during receive
+	}
+
+	readHandler := func(filename string, w *io.PipeWriter) {
+		for i := 0; i < 5; i++ {
+			_, err := w.Write(randomByteArray(64))
+			if err != nil {
+				panic(err)
+			}
+		}
+		// server "fail" during send
+	}
+
+	s = &Server{addr, writeHandler, readHandler, log}
+	go s.Serve()
+
+	c = &Client{addr, log}
+
+	var err error
+	c.Put("test", "octet", func(writer *io.PipeWriter) {
+		_, err = writer.Write(randomByteArray(5000))
+		writer.Close()
+	})
+	if err != ErrSendTimeout {
+		t.Fatalf("Send timeout expected, got %v", err)
+	}
+
+	buf := new(bytes.Buffer)
+	c.Get("test", "octet", func(reader *io.PipeReader) {
+		_, err = buf.ReadFrom(reader)
+	})
+	if err != ErrReceiveTimeout {
+		t.Fatalf("Receive timeout expected, got %v", err)
+	}
+}
+
 func randomByteArray(n int) []byte {
 	bs := make([]byte, n)
 	for i := 0; i < n; i++ {