diff --git a/xlsxwriter/packager.py b/xlsxwriter/packager.py
index 86b2bb47..92a97f14 100644
--- a/xlsxwriter/packager.py
+++ b/xlsxwriter/packager.py
@@ -35,7 +35,7 @@
 from .exceptions import EmptyChartSeries
 
 
-class Packager(object):
+class Packager():
     """
     A class for writing the Excel XLSX Packager file.
 
diff --git a/xlsxwriter/shape.py b/xlsxwriter/shape.py
index 6111ed6c..c3468ce1 100644
--- a/xlsxwriter/shape.py
+++ b/xlsxwriter/shape.py
@@ -9,7 +9,7 @@
 from warnings import warn
 
 
-class Shape(object):
+class Shape():
     """
     A class for to represent Excel XLSX shape objects.
 
diff --git a/xlsxwriter/sharedstrings.py b/xlsxwriter/sharedstrings.py
index fffdeac6..d628e71a 100644
--- a/xlsxwriter/sharedstrings.py
+++ b/xlsxwriter/sharedstrings.py
@@ -100,7 +100,7 @@ def _write_si(self, string):
 
 
 # A metadata class to store Excel strings between worksheets.
-class SharedStringTable(object):
+class SharedStringTable():
     """
     A class to track Excel shared strings between worksheets.
 
diff --git a/xlsxwriter/theme.py b/xlsxwriter/theme.py
index 1dd0f580..30d8a4bf 100644
--- a/xlsxwriter/theme.py
+++ b/xlsxwriter/theme.py
@@ -9,7 +9,7 @@
 from io import StringIO
 
 
-class Theme(object):
+class Theme():
     """
     A class for writing the Excel XLSX Theme file.
 
diff --git a/xlsxwriter/workbook.py b/xlsxwriter/workbook.py
index ff8549ca..93ac43cb 100644
--- a/xlsxwriter/workbook.py
+++ b/xlsxwriter/workbook.py
@@ -1769,7 +1769,7 @@ def _write_defined_name(self, defined_name):
 
 
 # A metadata class to share data between worksheets.
-class WorksheetMeta(object):
+class WorksheetMeta():
     """
     A class to track worksheets data such as the active sheet and the
     first sheet.
@@ -1782,7 +1782,7 @@ def __init__(self):
 
 
 # A helper class to share embedded images between worksheets.
-class EmbeddedImages(object):
+class EmbeddedImages():
     """
     A class to track duplicate embedded images between worksheets.
 
diff --git a/xlsxwriter/xmlwriter.py b/xlsxwriter/xmlwriter.py
index 37e43aad..b2551f34 100644
--- a/xlsxwriter/xmlwriter.py
+++ b/xlsxwriter/xmlwriter.py
@@ -18,7 +18,7 @@
 xml_escapes = re.compile('["&<>\n]')
 
 
-class XMLwriter(object):
+class XMLwriter():
     """
     Simple XML writer class.