diff --git a/ryu/lib/packet/dhcp.py b/ryu/lib/packet/dhcp.py
index bfc1f78c..eed7a113 100644
--- a/ryu/lib/packet/dhcp.py
+++ b/ryu/lib/packet/dhcp.py
@@ -149,7 +149,7 @@ class dhcp(packet_base.PacketBase):
     def __init__(self, op, chaddr, options, htype=_HARDWARE_TYPE_ETHERNET,
                  hlen=0, hops=0, xid=None, secs=0, flags=0,
                  ciaddr='0.0.0.0', yiaddr='0.0.0.0', siaddr='0.0.0.0',
-                 giaddr='0.0.0.0', sname=b'', boot_file=b''):
+                 giaddr='0.0.0.0', sname='', boot_file=b''):
         super(dhcp, self).__init__()
         self.op = op
         self.htype = htype
diff --git a/ryu/tests/unit/packet/test_dhcp.py b/ryu/tests/unit/packet/test_dhcp.py
index 92116ee8..1c24ef1a 100644
--- a/ryu/tests/unit/packet/test_dhcp.py
+++ b/ryu/tests/unit/packet/test_dhcp.py
@@ -41,7 +41,7 @@ class Test_dhcp_offer(unittest.TestCase):
     yiaddr = '192.168.20.20'
     siaddr = '192.168.30.30'
     giaddr = '192.168.40.40'
-    sname = b'abc'
+    sname = 'abc'
     boot_file = b''
 
     option_list = [
@@ -124,7 +124,7 @@ class Test_dhcp_offer(unittest.TestCase):
         eq_(self.giaddr, res.giaddr)
         eq_(self.chaddr, res.chaddr)
         # sname is 64 byte length. rest of data is filled by '\x00'.
-        eq_(self.sname.ljust(64, b'\x00'), res.sname)
+        eq_(self.sname.ljust(64, '\x00'), res.sname)
         # boof_file is 128 byte length. rest of data is filled by '\x00'.
         eq_(self.boot_file.ljust(128, b'\x00'), res.boot_file)
         eq_(str(self.options), str(res.options))
@@ -153,7 +153,7 @@ class Test_dhcp_offer(unittest.TestCase):
         eq_(self.giaddr, addrconv.ipv4.bin_to_text(res[10]))
         eq_(self.chaddr, addrconv.mac.bin_to_text(res[11][:6]))
         # sname is 64 byte length. rest of data is filled by '\x00'.
-        eq_(self.sname.ljust(64, b'\x00'), res[12])
+        eq_(self.sname.ljust(64, '\x00'), res[12].decode('ascii'))
         # boof_file is 128 byte length. rest of data is filled by '\x00'.
         eq_(self.boot_file.ljust(128, b'\x00'), res[13])
         options = dhcp.options.parser(