diff --git a/ryu/ofproto/ofproto_v1_3_parser.py b/ryu/ofproto/ofproto_v1_3_parser.py
index 62b56a70..85b80298 100644
--- a/ryu/ofproto/ofproto_v1_3_parser.py
+++ b/ryu/ofproto/ofproto_v1_3_parser.py
@@ -2268,7 +2268,7 @@ class OFPPort(ofproto_parser.namedtuple('OFPPort', (
         i = cls._fields.index('hw_addr')
         port[i] = addrconv.mac.bin_to_text(port[i])
         i = cls._fields.index('name')
-        port[i] = port[i].rstrip('\0')
+        port[i] = port[i].rstrip(b'\0')
         ofpport = cls(*port)
         ofpport.length = ofproto.OFP_PORT_SIZE
         return ofpport
@@ -3649,7 +3649,7 @@ class OFPDescStats(ofproto_parser.namedtuple('OFPDescStats', (
         desc = struct.unpack_from(ofproto.OFP_DESC_PACK_STR,
                                   buf, offset)
         desc = list(desc)
-        desc = [x.rstrip('\0') for x in desc]
+        desc = [x.rstrip(b'\0') for x in desc]
         stats = cls(*desc)
         stats.length = ofproto.OFP_DESC_SIZE
         return stats
@@ -4916,7 +4916,7 @@ class OFPTableFeaturesStats(StringifyMixin):
          table_features.max_entries
          ) = struct.unpack_from(ofproto.OFP_TABLE_FEATURES_PACK_STR,
                                 buf, offset)
-        table_features.name = name.rstrip('\0')
+        table_features.name = name.rstrip(b'\0')
 
         props = []
         rest = buf[offset + ofproto.OFP_TABLE_FEATURES_SIZE:
diff --git a/ryu/ofproto/ofproto_v1_4_parser.py b/ryu/ofproto/ofproto_v1_4_parser.py
index b359f025..b9b873fc 100644
--- a/ryu/ofproto/ofproto_v1_4_parser.py
+++ b/ryu/ofproto/ofproto_v1_4_parser.py
@@ -1841,7 +1841,7 @@ class OFPPort(StringifyMixin):
         (port_no, length, hw_addr, name, config, state) = struct.unpack_from(
             ofproto.OFP_PORT_PACK_STR, buf, offset)
         hw_addr = addrconv.mac.bin_to_text(hw_addr)
-        name = name.rstrip('\0')
+        name = name.rstrip(b'\0')
         props = []
         rest = buf[offset + ofproto.OFP_PORT_SIZE:offset + length]
         while rest:
@@ -2101,7 +2101,7 @@ class OFPDescStats(ofproto_parser.namedtuple('OFPDescStats', (
         desc = struct.unpack_from(ofproto.OFP_DESC_PACK_STR,
                                   buf, offset)
         desc = list(desc)
-        desc = [x.rstrip('\0') for x in desc]
+        desc = [x.rstrip(b'\0') for x in desc]
         stats = cls(*desc)
         stats.length = ofproto.OFP_DESC_SIZE
         return stats
@@ -2197,7 +2197,7 @@ class OFPTableFeaturesStats(StringifyMixin):
          table_features.max_entries
          ) = struct.unpack_from(ofproto.OFP_TABLE_FEATURES_PACK_STR,
                                 buf, offset)
-        table_features.name = name.rstrip('\0')
+        table_features.name = name.rstrip(b'\0')
 
         props = []
         rest = buf[offset + ofproto.OFP_TABLE_FEATURES_SIZE:
diff --git a/ryu/tests/unit/test_utils.py b/ryu/tests/unit/test_utils.py
index 70843cf4..64886c3c 100644
--- a/ryu/tests/unit/test_utils.py
+++ b/ryu/tests/unit/test_utils.py
@@ -33,13 +33,13 @@ class Test_utils(unittest.TestCase):
     def test_hex_array_string(self):
         ''' Test string conversion into array of hexes '''
         expected_result = '0x1 0x2 0x3 0x4'
-        data = '\01\02\03\04'
+        data = b'\01\02\03\04'
         eq_(expected_result, utils.hex_array(data))
 
     def test_hex_array_bytearray(self):
         ''' Test bytearray conversion into array of hexes '''
         expected_result = '0x1 0x2 0x3 0x4'
-        data = bytearray('\01\02\03\04')
+        data = bytearray(b'\01\02\03\04')
         eq_(expected_result, utils.hex_array(data))
 
     def test_hex_array_invalid(self):