diff --git a/atrcopy/ataridos.py b/atrcopy/ataridos.py
index ba4403c..3b4d08b 100644
--- a/atrcopy/ataridos.py
+++ b/atrcopy/ataridos.py
@@ -256,7 +256,7 @@ class XexSegment(ObjSegment):
     savers = [SegmentSaver, XexSegmentSaver]
 
 
-class AtariDosFile(object):
+class AtariDosFile:
     """Parse a binary chunk into segments according to the Atari DOS object
     file format.
     
diff --git a/atrcopy/cartridge.py b/atrcopy/cartridge.py
index 425b6db..70cba57 100644
--- a/atrcopy/cartridge.py
+++ b/atrcopy/cartridge.py
@@ -111,7 +111,7 @@ def get_cart(cart_type):
         raise errors.InvalidDiskImage("Unsupported cart type %d" % cart_type)
 
 
-class A8CartHeader(object):
+class A8CartHeader:
     # Atari Cart format described by https://sourceforge.net/p/atari800/source/ci/master/tree/DOC/cart.txt  NOTE: Big endian!
     format = np.dtype([
         ('magic', '|S4'),
diff --git a/atrcopy/diskimages.py b/atrcopy/diskimages.py
index be6dea0..6fd7551 100644
--- a/atrcopy/diskimages.py
+++ b/atrcopy/diskimages.py
@@ -12,7 +12,7 @@ except NameError:
     _xd = False
 
 
-class BaseHeader(object):
+class BaseHeader:
     file_format = "generic"  # text descriptor of file format
     sector_class = WriteableSector
 
@@ -91,7 +91,7 @@ class BaseHeader(object):
         return self.sector_class(self.sector_size, data)
 
 
-class DiskImageBase(object):
+class DiskImageBase:
     def __init__(self, rawdata, filename="", create=False):
         self.rawdata = rawdata
         self.bytes = self.rawdata.get_data()
diff --git a/atrcopy/dos33.py b/atrcopy/dos33.py
index 1a23dd5..c711d2b 100644
--- a/atrcopy/dos33.py
+++ b/atrcopy/dos33.py
@@ -629,7 +629,7 @@ class Dos33DiskImage(DiskImageBase):
         return image, 'B'
 
 
-class Dos33BinFile(object):
+class Dos33BinFile:
     """Parse a binary chunk into segments according to the DOS 3.3 binary
     dump format
     """
diff --git a/atrcopy/parsers.py b/atrcopy/parsers.py
index ff55843..15a3ea4 100644
--- a/atrcopy/parsers.py
+++ b/atrcopy/parsers.py
@@ -15,7 +15,7 @@ import logging
 log = logging.getLogger(__name__)
 
 
-class SegmentParser(object):
+class SegmentParser:
     menu_name = ""
     image_type = None
     container_segment = DefaultSegment
diff --git a/atrcopy/segments.py b/atrcopy/segments.py
index 37f945c..2288b3f 100644
--- a/atrcopy/segments.py
+++ b/atrcopy/segments.py
@@ -57,7 +57,7 @@ def get_style_mask(**kwargs):
     return 0xff ^ bits
 
 
-class SegmentSaver(object):
+class SegmentSaver:
     export_data_name = "Raw Data"
     export_extensions = [".dat"]
 
@@ -66,7 +66,7 @@ class SegmentSaver(object):
         return segment.tobytes()
 
 
-class BSAVESaver(object):
+class BSAVESaver:
     export_data_name = "Apple ][ Binary"
     export_extensions = [".bsave"]
 
@@ -80,7 +80,7 @@ class BSAVESaver(object):
         return header.tobytes() + segment.tobytes()
 
 
-class OrderWrapper(object):
+class OrderWrapper:
     """Wrapper for numpy data so that manipulations can use normal numpy syntax
     and still affect the data according to the byte ordering.
 
@@ -132,7 +132,7 @@ class OrderWrapper(object):
         return self.np_data[self.order].tobytes()
 
 
-class UserExtraData(object):
+class UserExtraData:
     def __init__(self):
         self.comments = dict()
         self.user_data = dict()
@@ -140,7 +140,7 @@ class UserExtraData(object):
             self.user_data[i] = dict()
 
 
-class SegmentData(object):
+class SegmentData:
     def __init__(self, data, style=None, extra=None, debug=False, order=None):
         """Storage for raw data
 
@@ -388,7 +388,7 @@ class SegmentData(object):
         return r
 
 
-class DefaultSegment(object):
+class DefaultSegment:
     savers = [SegmentSaver, BSAVESaver]
     can_resize_default = False
 
diff --git a/atrcopy/utils.py b/atrcopy/utils.py
index f3f4419..ad022e9 100644
--- a/atrcopy/utils.py
+++ b/atrcopy/utils.py
@@ -60,7 +60,7 @@ def text_to_int(text, default_base="hex"):
     return value
 
 
-class WriteableSector(object):
+class WriteableSector:
     def __init__(self, sector_size, data=None, num=-1):
         self._sector_num = num
         self._next_sector = 0
@@ -109,7 +109,7 @@ class WriteableSector(object):
         return data[count:]
 
 
-class BaseSectorList(object):
+class BaseSectorList:
     def __init__(self, header):
         self.header = header
         self.sector_size = header.sector_size
@@ -150,7 +150,7 @@ class BaseSectorList(object):
         self.sectors.extend(sectors)
 
 
-class Dirent(object):
+class Dirent:
     """Abstract base class for a directory entry
 
     """
diff --git a/test/test_add_file.py b/test/test_add_file.py
index 6458a48..afee838 100644
--- a/test/test_add_file.py
+++ b/test/test_add_file.py
@@ -8,7 +8,7 @@ from atrcopy import SegmentData, AtariDosDiskImage, Dos33DiskImage
 from atrcopy import errors
 
 
-class BaseFilesystemModifyTest(object):
+class BaseFilesystemModifyTest:
     diskimage_type = None
     sample_data = None
     num_files_in_sample = 0
diff --git a/test/test_ataridos.py b/test/test_ataridos.py
index b5ab349..3137726 100644
--- a/test/test_ataridos.py
+++ b/test/test_ataridos.py
@@ -6,7 +6,7 @@ from atrcopy import SegmentData, AtariDosFile, DefaultSegment, XexContainerSegme
 
 
 
-class TestAtariDosFile(object):
+class TestAtariDosFile:
     def setup(self):
         pass
 
diff --git a/test/test_cart.py b/test/test_cart.py
index 33b8ff9..627a53c 100644
--- a/test/test_cart.py
+++ b/test/test_cart.py
@@ -7,7 +7,7 @@ from atrcopy import AtariCartImage, SegmentData
 from atrcopy import errors
 
 
-class TestAtariCart(object):
+class TestAtariCart:
     def setup(self):
         pass
 
diff --git a/test/test_create.py b/test/test_create.py
index 3e1b70b..40d8dfe 100644
--- a/test/test_create.py
+++ b/test/test_create.py
@@ -15,7 +15,7 @@ def get_image(file_name, diskimage_type):
     return image
 
 
-class BaseCreateTest(object):
+class BaseCreateTest:
     diskimage_type = None
 
     def get_exe_segments(self):
diff --git a/test/test_jsonpickle.py b/test/test_jsonpickle.py
index c4692af..4f8a2f4 100644
--- a/test/test_jsonpickle.py
+++ b/test/test_jsonpickle.py
@@ -12,7 +12,7 @@ import numpy as np
 from atrcopy import DefaultSegment, SegmentData
 
 
-class TestJsonPickle(object):
+class TestJsonPickle:
     def setup(self):
         data = np.arange(2048, dtype=np.uint8)
         self.segment = DefaultSegment(SegmentData(data))
diff --git a/test/test_kboot.py b/test/test_kboot.py
index a9ba76e..3e19649 100644
--- a/test/test_kboot.py
+++ b/test/test_kboot.py
@@ -10,7 +10,7 @@ from mock import *
 from atrcopy import SegmentData, KBootImage, add_xexboot_header, add_atr_header
 
 
-class TestKbootHeader(object):
+class TestKbootHeader:
     def setup(self):
         pass
 
diff --git a/test/test_segment.py b/test/test_segment.py
index 263df63..3ed9c6e 100644
--- a/test/test_segment.py
+++ b/test/test_segment.py
@@ -18,7 +18,7 @@ def get_indexed(segment, num, scale):
     s = DefaultSegment(raw, segment.origin + indexes[0])
     return s, indexes
 
-class TestSegment1(object):
+class TestSegment1:
     def setup(self):
         self.segments = []
         for i in range(8):
@@ -68,7 +68,7 @@ class TestSegment1(object):
             assert not np.all((c.data[:] - s.data[:]) == 0)
 
 
-class TestIndexed(object):
+class TestIndexed:
     def setup(self):
         data = np.arange(4096, dtype=np.uint8)
         data[1::2] = np.repeat(np.arange(16, dtype=np.uint8), 128)
@@ -242,7 +242,7 @@ class TestIndexed(object):
         assert not np.all((c.data[:] - s.data[:]) == 0)
 
 
-class TestComments(object):
+class TestComments:
     def setup(self):
         data = np.ones([4000], dtype=np.uint8)
         r = SegmentData(data)
@@ -392,7 +392,7 @@ class TestComments(object):
             assert set(item1[3].values()) == set(item2[3].values())
 
 
-class TestResize(object):
+class TestResize:
     def setup(self):
         data = np.arange(4096, dtype=np.uint8)
         data[1::2] = np.repeat(np.arange(16, dtype=np.uint8), 128)
diff --git a/test/test_serialize.py b/test/test_serialize.py
index 7215cdb..fea334e 100644
--- a/test/test_serialize.py
+++ b/test/test_serialize.py
@@ -10,7 +10,7 @@ import pytest
 from atrcopy import DefaultSegment, SegmentData, get_xex, interleave_segments
 
 
-class TestSegment(object):
+class TestSegment:
     def setup(self):
         data = np.ones([4000], dtype=np.uint8)
         r = SegmentData(data)
diff --git a/test/test_utils.py b/test/test_utils.py
index 493bde2..43b8847 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -3,7 +3,7 @@ from mock import *
 from atrcopy import utils
 
 
-class TestTextToInt(object):
+class TestTextToInt:
     def setup(self):
         pass