diff -rU 3 a/vobject/base.py b/vobject/base.py
--- a/vobject/base.py	2024-12-16 08:15:20.000000000 +0100
+++ b/vobject/base.py	2025-05-08 10:54:19.517509757 +0200
@@ -6,7 +6,7 @@
 import codecs
 import logging
 import re
-import six
+import io
 import sys
 
 # Package version
@@ -858,7 +858,7 @@
     Quoted-printable data will be decoded in the Behavior decoding phase.
 
     # We're leaving this test in for awhile, because the unittest was ugly and dumb.
-    >>> from six import StringIO
+    >>> from io import StringIO
     >>> f=StringIO(testLines)
     >>> for n, l in enumerate(getLogicalLines(f)):
     ...     print("Line %s: %s" % (n, l[0]))
@@ -881,7 +881,7 @@
 
     else:
         quotedPrintable = False
-        newbuffer = six.StringIO
+        newbuffer = io.StringIO
         logicalLine = newbuffer()
         lineNumber = 0
         lineStartNumber = 0
@@ -996,7 +996,7 @@
     """
     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:
@@ -1018,7 +1018,7 @@
         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 + '.')
@@ -1082,7 +1082,7 @@
     Generate one Component at a time from a stream.
     """
     if isinstance(streamOrString, basestring):
-        stream = six.StringIO(streamOrString)
+        stream = io.StringIO(streamOrString)
     else:
         stream = streamOrString
 
diff -rU 3 a/vobject/hcalendar.py b/vobject/hcalendar.py
--- a/vobject/hcalendar.py	2024-10-01 16:46:45.000000000 +0200
+++ b/vobject/hcalendar.py	2025-05-08 10:55:12.047890349 +0200
@@ -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
 
diff -rU 3 a/vobject/icalendar.py b/vobject/icalendar.py
--- a/vobject/icalendar.py	2024-12-16 08:09:54.000000000 +0100
+++ b/vobject/icalendar.py	2025-05-08 10:57:12.542858557 +0200
@@ -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
@@ -569,7 +569,7 @@
                     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])
 
@@ -1010,7 +1010,7 @@
             transformed = obj
             undoTransform = False
         out = None
-        outbuf = buf or six.StringIO()
+        outbuf = buf or io.StringIO()
         if obj.group is None:
             groupString = ''
         else: