diff --git a/bytesconv/byteResult.go b/bytesconv/byteResult.go
index cb0cba4..fc72915 100644
--- a/bytesconv/byteResult.go
+++ b/bytesconv/byteResult.go
@@ -3,9 +3,10 @@ package bytesconv
 import (
 	"encoding/base64"
 	"encoding/hex"
-	"strings"
 )
 
+const hextable = "0123456789ABCDEF"
+
 type BytesResult []byte
 
 func (r BytesResult) Hex() string {
@@ -13,7 +14,15 @@ func (r BytesResult) Hex() string {
 }
 
 func (r BytesResult) UppercaseHex() string {
-	return strings.ToUpper(hex.EncodeToString(r))
+	dst := make([]byte, hex.EncodedLen(len(r)))
+	j := 0
+	for _, v := range r {
+		dst[j] = hextable[v>>4]
+		dst[j+1] = hextable[v&0x0f]
+		j += 2
+	}
+
+	return BytesToString(dst)
 }
 
 func (r BytesResult) Base64() string {
diff --git a/bytesconv/bytes_result_test.go b/bytesconv/bytes_result_test.go
new file mode 100644
index 0000000..4f3dbcf
--- /dev/null
+++ b/bytesconv/bytes_result_test.go
@@ -0,0 +1,18 @@
+package bytesconv_test
+
+import (
+	"testing"
+
+	"github.com/charlienet/go-mixed/bytesconv"
+	"github.com/charlienet/go-mixed/rand"
+)
+
+func TestHexUppercase(t *testing.T) {
+	b, _ := rand.RandBytes(12)
+
+	l := bytesconv.BytesResult(b).Hex()
+	t.Log(l)
+
+	u := bytesconv.BytesResult(b).UppercaseHex()
+	t.Log(u)
+}