diff --git a/ledis/t_hash.go b/ledis/t_hash.go
index 952ddae..a2e0bd3 100644
--- a/ledis/t_hash.go
+++ b/ledis/t_hash.go
@@ -3,6 +3,7 @@ package ledis
 import (
 	"encoding/binary"
 	"errors"
+	"github.com/siddontang/go/num"
 	"github.com/siddontang/ledisdb/store"
 	"time"
 )
@@ -332,7 +333,7 @@ func (db *DB) HIncrBy(key []byte, field []byte, delta int64) (int64, error) {
 
 	n += delta
 
-	_, err = db.hSetItem(key, field, StrPutInt64(n))
+	_, err = db.hSetItem(key, field, num.FormatInt64ToSlice(n))
 	if err != nil {
 		return 0, err
 	}
diff --git a/ledis/t_kv.go b/ledis/t_kv.go
index ce0874a..14d477b 100644
--- a/ledis/t_kv.go
+++ b/ledis/t_kv.go
@@ -2,6 +2,7 @@ package ledis
 
 import (
 	"errors"
+	"github.com/siddontang/go/num"
 	"time"
 )
 
@@ -75,7 +76,7 @@ func (db *DB) incr(key []byte, delta int64) (int64, error) {
 
 	n += delta
 
-	t.Put(key, StrPutInt64(n))
+	t.Put(key, num.FormatInt64ToSlice(n))
 
 	err = t.Commit()
 	return n, err
diff --git a/ledis/t_set.go b/ledis/t_set.go
index 7f41f53..2eb6c4c 100644
--- a/ledis/t_set.go
+++ b/ledis/t_set.go
@@ -509,14 +509,14 @@ func (db *DB) sStoreGeneric(dstKey []byte, optType byte, keys ...[]byte) (int64,
 		t.Put(ek, nil)
 	}
 
-	var num = int64(len(v))
+	var n = int64(len(v))
 	sk := db.sEncodeSizeKey(dstKey)
-	t.Put(sk, PutInt64(num))
+	t.Put(sk, PutInt64(n))
 
 	if err = t.Commit(); err != nil {
 		return 0, err
 	}
-	return num, nil
+	return n, nil
 }
 
 func (db *DB) SClear(key []byte) (int64, error) {
diff --git a/ledis/t_zset.go b/ledis/t_zset.go
index d7cb2b1..3a2336f 100644
--- a/ledis/t_zset.go
+++ b/ledis/t_zset.go
@@ -858,14 +858,14 @@ func (db *DB) ZUnionStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 		}
 	}
 
-	var num = int64(len(destMap))
+	var n = int64(len(destMap))
 	sk := db.zEncodeSizeKey(destKey)
-	t.Put(sk, PutInt64(num))
+	t.Put(sk, PutInt64(n))
 
 	if err := t.Commit(); err != nil {
 		return 0, err
 	}
-	return num, nil
+	return n, nil
 }
 
 func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, aggregate byte) (int64, error) {
@@ -926,14 +926,14 @@ func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 		}
 	}
 
-	var num int64 = int64(len(destMap))
+	var n int64 = int64(len(destMap))
 	sk := db.zEncodeSizeKey(destKey)
-	t.Put(sk, PutInt64(num))
+	t.Put(sk, PutInt64(n))
 
 	if err := t.Commit(); err != nil {
 		return 0, err
 	}
-	return num, nil
+	return n, nil
 }
 
 func (db *DB) ZScan(key []byte, count int, inclusive bool, match string) ([][]byte, error) {
diff --git a/ledis/util.go b/ledis/util.go
index 9454532..a0abdd0 100644
--- a/ledis/util.go
+++ b/ledis/util.go
@@ -4,13 +4,16 @@ import (
 	"encoding/binary"
 	"errors"
 	"github.com/siddontang/go/hack"
-	"reflect"
 	"strconv"
-	"unsafe"
 )
 
 var errIntNumber = errors.New("invalid integer")
 
+/*
+	Below I forget why I use little endian to store int.
+	Maybe I was foolish at that time.
+*/
+
 func Int64(v []byte, err error) (int64, error) {
 	if err != nil {
 		return 0, err
@@ -36,11 +39,8 @@ func Uint64(v []byte, err error) (uint64, error) {
 }
 
 func PutInt64(v int64) []byte {
-	var b []byte
-	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
-	pbytes.Data = uintptr(unsafe.Pointer(&v))
-	pbytes.Len = 8
-	pbytes.Cap = 8
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, uint64(v))
 	return b
 }
 
@@ -86,14 +86,6 @@ func StrInt8(v []byte, err error) (int8, error) {
 	}
 }
 
-func StrPutInt64(v int64) []byte {
-	return strconv.AppendInt(nil, v, 10)
-}
-
-func StrPutUint64(v uint64) []byte {
-	return strconv.AppendUint(nil, v, 10)
-}
-
 func AsyncNotify(ch chan struct{}) {
 	select {
 	case ch <- struct{}{}:
diff --git a/server/client_resp.go b/server/client_resp.go
index ed72108..1b50bc3 100644
--- a/server/client_resp.go
+++ b/server/client_resp.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"github.com/siddontang/go/hack"
 	"github.com/siddontang/go/log"
+	"github.com/siddontang/go/num"
 	"github.com/siddontang/ledisdb/ledis"
 	"io"
 	"net"
@@ -171,7 +172,7 @@ func (w *respWriter) writeStatus(status string) {
 
 func (w *respWriter) writeInteger(n int64) {
 	w.buff.WriteByte(':')
-	w.buff.Write(ledis.StrPutInt64(n))
+	w.buff.Write(num.FormatInt64ToSlice(n))
 	w.buff.Write(Delims)
 }
 
@@ -266,7 +267,7 @@ func (w *respWriter) writeScorePairArray(lst []ledis.ScorePair, withScores bool)
 			w.writeBulk(lst[i].Member)
 
 			if withScores {
-				w.writeBulk(ledis.StrPutInt64(lst[i].Score))
+				w.writeBulk(num.FormatInt64ToSlice(lst[i].Score))
 			}
 		}
 	}
diff --git a/server/cmd_zset.go b/server/cmd_zset.go
index 9c58f5b..4763683 100644
--- a/server/cmd_zset.go
+++ b/server/cmd_zset.go
@@ -3,7 +3,7 @@ package server
 import (
 	"errors"
 	"github.com/siddontang/go/hack"
-
+	"github.com/siddontang/go/num"
 	"github.com/siddontang/ledisdb/ledis"
 	"math"
 	"strconv"
@@ -75,7 +75,7 @@ func zscoreCommand(c *client) error {
 			return err
 		}
 	} else {
-		c.resp.writeBulk(ledis.StrPutInt64(s))
+		c.resp.writeBulk(num.FormatInt64ToSlice(s))
 	}
 
 	return nil
@@ -112,7 +112,7 @@ func zincrbyCommand(c *client) error {
 	v, err := c.db.ZIncrBy(key, delta, args[2])
 
 	if err == nil {
-		c.resp.writeBulk(ledis.StrPutInt64(v))
+		c.resp.writeBulk(num.FormatInt64ToSlice(v))
 	}
 
 	return err
diff --git a/server/script.go b/server/script.go
index 24566c3..711b412 100644
--- a/server/script.go
+++ b/server/script.go
@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"github.com/siddontang/go/hack"
+	"github.com/siddontang/go/num"
 	"github.com/siddontang/ledisdb/ledis"
 	"github.com/siddontang/ledisdb/lua"
 	"io"
@@ -115,7 +116,7 @@ func (w *luaWriter) writeScorePairArray(lst []ledis.ScorePair, withScores bool)
 			w.l.PushString(hack.String(v.Member))
 			w.l.RawSeti(-2, 2*i+1)
 
-			w.l.PushString(hack.String(ledis.StrPutInt64(v.Score)))
+			w.l.PushString(hack.String(num.FormatInt64ToSlice(v.Score)))
 			w.l.RawSeti(-2, 2*i+2)
 		}
 	} else {