diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index ddb520b..f3fd05b 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -7,4 +7,4 @@ Max Borghino <fmborghino@gmail.com>
 Mohammad Abu-Garbeyyeh <github@mohammadag.com>
 Josip Delic <delijati@gmail.com>
 Greg E. <greateggsgreg@gmail.com>
-
+Yongguang Lin <linsoft@yeah.net>
diff --git a/adb/adb_commands.py b/adb/adb_commands.py
index 9d107d9..411e49d 100644
--- a/adb/adb_commands.py
+++ b/adb/adb_commands.py
@@ -127,7 +127,7 @@ def ConnectDevice(self, port_path=None, serial=None, default_timeout_ms=None, **
         # If there isnt a handle override (used by tests), build one here
         if 'handle' in kwargs:
             self._handle = kwargs.pop('handle')
-        elif serial and b':' in serial:
+        elif serial and ':' in serial:
             self._handle = common.TcpHandle(serial, timeout_ms=default_timeout_ms)
         else:
             self._handle = common.UsbHandle.FindAndOpen(
diff --git a/adb/common.py b/adb/common.py
index a68414f..1e31351 100644
--- a/adb/common.py
+++ b/adb/common.py
@@ -298,8 +298,8 @@ def __init__(self, serial, timeout_ms=None):
 
         Host may be an IP address or a host name.
         """
-        if b':' in serial:
-            (host, port) = serial.split(b':')
+        if ':' in serial:
+            (host, port) = serial.split(':')
         else:
             host = serial
             port = 5555
diff --git a/adb/sign_pythonrsa.py b/adb/sign_pythonrsa.py
index bc6a221..a401a4c 100644
--- a/adb/sign_pythonrsa.py
+++ b/adb/sign_pythonrsa.py
@@ -24,7 +24,7 @@
 # hashing algo for this.
 class _Accum(object):
     def __init__(self):
-        self._buf = ''
+        self._buf = b''
 
     def update(self, msg):
         self._buf += msg