bencode/api.go    |  9 ++++-----
 bencode/encode.go | 19 ++++++++-----------

diff --git a/bencode/api.go b/bencode/api.go
index 6c311e118047d75c2293307a89004ab28cae9b75..15687a8ce31e14ebb6726a1d11423c0ae95dcd6d 100644
--- a/bencode/api.go
+++ b/bencode/api.go
@@ -1,7 +1,6 @@
 package bencode
 
 import (
-	"bufio"
 	"bytes"
 	"fmt"
 	"io"
@@ -111,11 +110,11 @@ type Unmarshaler interface {
 	UnmarshalBencode([]byte) error
 }
 
-// Marshal the value 'v' to the bencode form, return the result as []byte and an
-// error if any.
+// Marshal the value 'v' to the bencode form, return the result as []byte and
+// an error if any.
 func Marshal(v interface{}) ([]byte, error) {
 	var buf bytes.Buffer
-	e := Encoder{w: bufio.NewWriter(&buf)}
+	e := Encoder{w: &buf}
 	err := e.Encode(v)
 	if err != nil {
 		return nil, err
@@ -154,5 +153,5 @@ 	return &Decoder{r: &scanner{r: r}}
 }
 
 func NewEncoder(w io.Writer) *Encoder {
-	return &Encoder{w: bufio.NewWriter(w)}
+	return &Encoder{w: w}
 }
diff --git a/bencode/encode.go b/bencode/encode.go
index d6b6334f38331c857d79ed3b7194b3c3906845da..2bbf0bad5ec9558d3604599fd3c463b4baacfdfe 100644
--- a/bencode/encode.go
+++ b/bencode/encode.go
@@ -17,11 +17,7 @@ 	return missinggo.IsEmptyValue(v)
 }
 
 type Encoder struct {
-	w interface {
-		Flush() error
-		io.Writer
-		WriteString(string) (int, error)
-	}
+	w       io.Writer
 	scratch [64]byte
 }
 
@@ -42,7 +38,7 @@ 			}
 		}
 	}()
 	e.reflectValue(reflect.ValueOf(v))
-	return e.w.Flush()
+	return nil
 }
 
 type string_values []reflect.Value
@@ -60,9 +56,10 @@ 	}
 }
 
 func (e *Encoder) writeString(s string) {
-	_, err := e.w.WriteString(s)
-	if err != nil {
-		panic(err)
+	for s != "" {
+		n := copy(e.scratch[:], s)
+		s = s[n:]
+		e.write(e.scratch[:n])
 	}
 }
 
@@ -129,13 +126,13 @@ 		} else {
 			e.writeString("i0e")
 		}
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		b := strconv.AppendInt(e.scratch[:0], v.Int(), 10)
 		e.writeString("i")
+		b := strconv.AppendInt(e.scratch[:0], v.Int(), 10)
 		e.write(b)
 		e.writeString("e")
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
-		b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10)
 		e.writeString("i")
+		b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10)
 		e.write(b)
 		e.writeString("e")
 	case reflect.String: