diff --git a/expression/expressions/convert.go b/expression/expressions/convert.go
index b636cb5..8fc7918 100644
--- a/expression/expressions/convert.go
+++ b/expression/expressions/convert.go
@@ -17,11 +17,12 @@ import (
        "fmt"
        "strings"

-       iconv "github.com/djimenez/iconv-go"
        "github.com/juju/errors"
        "github.com/ngaut/log"
        "github.com/pingcap/tidb/context"
        "github.com/pingcap/tidb/expression"
+       "golang.org/x/net/html/charset"
+       "golang.org/x/text/transform"
 )

 // FunctionConvert provides a way to convert data between different character sets.
@@ -74,7 +75,13 @@ func (f *FunctionConvert) Eval(ctx context.Context, args map[interface{}]interfa
        } else if strings.ToLower(f.Charset) == "utf8mb4" {
                return value, nil
        }
-       target, err := iconv.ConvertString(str, "utf-8", f.Charset)
+
+       encoding, _ := charset.Lookup(f.Charset)
+       if encoding == nil {
+               return nil, fmt.Errorf("unknow char decoder %s", f.Charset)
+       }
+
+       target, _, err := transform.String(encoding.NewDecoder(), str)
        if err != nil {
                log.Errorf("Convert %s to %s with error: %v", str, f.Charset, err)
                return nil, errors.Trace(err)