diff --git a/models/git_diff.go b/models/git_diff.go
index 4bbe3c0e..7e91626f 100644
--- a/models/git_diff.go
+++ b/models/git_diff.go
@@ -14,12 +14,14 @@ import (
 	"strings"
 	"time"
 
+	"golang.org/x/net/html/charset"
+	"golang.org/x/text/transform"
+
 	"github.com/Unknwon/com"
 
 	"github.com/gogits/gogs/modules/base"
 	"github.com/gogits/gogs/modules/git"
 	"github.com/gogits/gogs/modules/log"
-	"github.com/gogits/gogs/modules/mahonia"
 	"github.com/gogits/gogs/modules/process"
 )
 
@@ -192,14 +194,18 @@ func ParsePatch(pid int64, maxlines int, cmd *exec.Cmd, reader io.Reader) (*Diff
 	}
 
 	// FIXME: use first 30 lines to detect file encoding.
-	charset, err := base.DetectEncoding(buf.Bytes())
-	if charset != "utf8" && err == nil {
-		decoder := mahonia.NewDecoder(charset)
-		if decoder != nil {
+	charsetLabel, err := base.DetectEncoding(buf.Bytes())
+	if charsetLabel != "utf8" && err == nil {
+		encoding, _ := charset.Lookup(charsetLabel)
+
+		if encoding != nil {
+			d := encoding.NewDecoder()
 			for _, f := range diff.Files {
 				for _, sec := range f.Sections {
 					for _, l := range sec.Lines {
-						l.Content = decoder.ConvertString(l.Content)
+						if c, _, err := transform.String(d, l.Content); err == nil {
+							l.Content = c
+						}
 					}
 				}
 			}
diff --git a/modules/base/template.go b/modules/base/template.go
index 462269aa..9107f3e1 100644
--- a/modules/base/template.go
+++ b/modules/base/template.go
@@ -7,14 +7,15 @@ package base
 import (
 	"container/list"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"html/template"
 	"runtime"
 	"strings"
 	"time"
 
-	"github.com/gogits/gogs/modules/mahonia"
+	"golang.org/x/net/html/charset"
+	"golang.org/x/text/transform"
+
 	"github.com/gogits/gogs/modules/setting"
 	"github.com/saintfish/chardet"
 )
@@ -54,20 +55,30 @@ func DetectEncoding(content []byte) (string, error) {
 }
 
 func ToUtf8WithErr(content []byte) (error, string) {
-	charset, err := DetectEncoding(content)
+	charsetLabel, err := DetectEncoding(content)
 	if err != nil {
 		return err, ""
 	}
 
-	if charset == "utf8" {
+	if charsetLabel == "utf8" {
 		return nil, string(content)
 	}
 
-	decoder := mahonia.NewDecoder(charset)
-	if decoder != nil {
-		return nil, decoder.ConvertString(string(content))
+	encoding, _ := charset.Lookup(charsetLabel)
+
+	if encoding == nil {
+		return fmt.Errorf("unknow char decoder %s", charsetLabel), string(content)
 	}
-	return errors.New("unknow char decoder"), string(content)
+
+	result, n, err := transform.String(encoding.NewDecoder(), string(content))
+
+	// If there is an error, we concatenate the nicely decoded part and the
+	// original left over. This way we won't loose data.
+	if err != nil {
+		result = result + string(content[n:])
+	}
+
+	return err, result
 }
 
 func ToUtf8(content string) string {