--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,7 @@
       include_package_data = True,
       install_requires=["python-dateutil >= 2.5.0; python_version < '3.10'",
                         "python-dateutil >= 2.7.0; python_version >= '3.10'",
-                        "pytz", 'six'],
+                        "pytz"],
       platforms = ["any"],
       packages = find_packages(),
       description = "A full-featured Python package for parsing and creating "
--- a/vobject/base.py
+++ b/vobject/base.py
@@ -6,7 +6,7 @@
 import codecs
 import logging
 import re
-import six
+import io
 import sys
 
 # ------------------------------------ Python 2/3 compatibility challenges  ----
@@ -877,7 +877,7 @@
 
     else:
         quotedPrintable = False
-        newbuffer = six.StringIO
+        newbuffer = io.StringIO
         logicalLine = newbuffer()
         lineNumber = 0
         lineStartNumber = 0
@@ -992,7 +992,7 @@
     """
     Encode and fold obj and its children, write to buf or return a string.
     """
-    outbuf = buf or six.StringIO()
+    outbuf = buf or io.StringIO()
 
     if isinstance(obj, Component):
         if obj.group is None:
@@ -1014,7 +1014,7 @@
         if obj.behavior and not startedEncoded:
             obj.behavior.encode(obj)
 
-        s = six.StringIO()
+        s = io.StringIO()
 
         if obj.group is not None:
             s.write(obj.group + '.')
@@ -1078,7 +1078,7 @@
     Generate one Component at a time from a stream.
     """
     if isinstance(streamOrString, basestring):
-        stream = six.StringIO(streamOrString)
+        stream = io.StringIO(streamOrString)
     else:
         stream = streamOrString
 
--- a/vobject/hcalendar.py
+++ b/vobject/hcalendar.py
@@ -28,7 +28,7 @@
 </span>
 """
 
-import six
+import io
 
 from datetime import date, datetime, timedelta
 
@@ -45,7 +45,7 @@
         Serialize iCalendar to HTML using the hCalendar microformat (http://microformats.org/wiki/hcalendar)
         """
 
-        outbuf = buf or six.StringIO()
+        outbuf = buf or io.StringIO()
         level = 0  # holds current indentation level
         tabwidth = 3
 
--- a/vobject/icalendar.py
+++ b/vobject/icalendar.py
@@ -10,7 +10,7 @@
 import base64
 
 from dateutil import rrule, tz
-import six
+import io
 
 try:
     import pytz
@@ -56,7 +56,7 @@
     """
     Take a string or unicode, turn it into unicode, decoding as utf-8
     """
-    if isinstance(s, six.binary_type):
+    if isinstance(s, bytes):
         s = s.decode('utf-8')
     return s
 
@@ -135,7 +135,7 @@
         good_lines = ('rdate', 'rrule', 'dtstart', 'tzname', 'tzoffsetfrom',
                       'tzoffsetto', 'tzid')
         # serialize encodes as utf-8, cStringIO will leave utf-8 alone
-        buffer = six.StringIO()
+        buffer = io.StringIO()
         # allow empty VTIMEZONEs
         if len(self.contents) == 0:
             return None
@@ -567,7 +567,7 @@
                     self.add(name).value = setlist
             elif name in RULENAMES:
                 for rule in setlist:
-                    buf = six.StringIO()
+                    buf = io.StringIO()
                     buf.write('FREQ=')
                     buf.write(FREQUENCIES[rule._freq])
 
@@ -1008,7 +1008,7 @@
             transformed = obj
             undoTransform = False
         out = None
-        outbuf = buf or six.StringIO()
+        outbuf = buf or io.StringIO()
         if obj.group is None:
             groupString = ''
         else: