diff --git a/src/ltui/base/bit.lua b/src/ltui/base/bit.lua
new file mode 100644
index 0000000..fcd5765
--- /dev/null
+++ b/src/ltui/base/bit.lua
@@ -0,0 +1,30 @@
+--!A cross-platform terminal ui library based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-2020, TBOOX Open Source Group.
+--
+-- @author      ruki
+-- @file        bit.lua
+--
+
+-- define module: bit
+local bit = bit or {}
+
+-- bit/and operation
+function bit.band(a, b)
+    return a & b
+end
+
+-- load bit module
+return bit
diff --git a/src/ltui/label.lua b/src/ltui/label.lua
index 62bdf3c..58215b6 100644
--- a/src/ltui/label.lua
+++ b/src/ltui/label.lua
@@ -19,11 +19,15 @@
 --
 
 -- load modules
-local log       = require("ltui/base/log")
-local view      = require("ltui/view")
-local event     = require("ltui/event")
-local action    = require("ltui/action")
-local curses    = require("ltui/curses")
+local log         = require("ltui/base/log")
+local view        = require("ltui/view")
+local event       = require("ltui/event")
+local action      = require("ltui/action")
+local curses      = require("ltui/curses")
+local luajit, bit = pcall(require, "bit")
+if not luajit then
+    bit = require("ltui/base/bit")
+end
 
 -- define module
 local label = label or view()
@@ -129,7 +133,7 @@ function label:splitext(text, width)
         while #line > width do
             local size = 0
             for i = 1, #line do
-                if (line:byte(i) & 0xc0) ~= 0x80 then
+                if bit.band(line:byte(i), 0xc0) ~= 0x80 then
                     size = size + 1
                     if size > width then
                         table.insert(result, line:sub(1, i - 1))
diff --git a/src/ltui/textedit.lua b/src/ltui/textedit.lua
index 7ade8df..181d19d 100644
--- a/src/ltui/textedit.lua
+++ b/src/ltui/textedit.lua
@@ -19,14 +19,18 @@
 --
 
 -- load modules
-local log       = require("ltui/base/log")
-local view      = require("ltui/view")
-local label     = require("ltui/label")
-local event     = require("ltui/event")
-local border    = require("ltui/border")
-local curses    = require("ltui/curses")
-local textarea  = require("ltui/textarea")
-local action    = require("ltui/action")
+local log         = require("ltui/base/log")
+local view        = require("ltui/view")
+local label       = require("ltui/label")
+local event       = require("ltui/event")
+local border      = require("ltui/border")
+local curses      = require("ltui/curses")
+local textarea    = require("ltui/textarea")
+local action      = require("ltui/action")
+local luajit, bit = pcall(require, "bit")
+if not luajit then
+    bit = require("ltui/base/bit")
+end
 
 -- define module
 local textedit = textedit or textarea()
@@ -85,7 +89,7 @@ function textedit:on_event(e)
             if #text > 0 then
                 local size = 1
                 -- while continuation byte
-                while (text:byte(#text - size + 1) & 0xc0) == 0x80 do
+                while bit.band(text:byte(#text - size + 1), 0xc0) == 0x80 do
                     size = size + 1
                 end
                 self:text_set(text:sub(1, #text - size))