diff --git a/.github/workflows/CI.yaml b/.github/workflows/CI.yaml
index e31b1b82..4f2ce23d 100644
--- a/.github/workflows/CI.yaml
+++ b/.github/workflows/CI.yaml
@@ -35,5 +35,5 @@ jobs:
       - name: Run MyPy
         if: matrix.python-version != 'pypy-3.7' 
         run: |
-          pip install enum34 mypy types-six
+          pip install mypy typed-ast
           ./mypy-run.sh
diff --git a/README.rst b/README.rst
index 2d3cc79f..b5f9f6a4 100644
--- a/README.rst
+++ b/README.rst
@@ -32,10 +32,10 @@ Alternative
 -----------
 
 If you choose not to install ``stone`` using the method above, you will need
-to ensure that you have the Python packages ``ply`` and ``six``, which can be
+to ensure that you have the Python package ``ply``, which can be
 installed through ``pip``::
 
-    $ pip install "ply>=3.4" "six>=1.3.0" "typing>=3.5.2"
+    $ pip install "ply>=3.4" "typing>=3.5.2"
 
 If the ``stone`` package is in your PYTHONPATH, you can replace ``stone``
 with ``python -m stone.cli`` as follows::
diff --git a/requirements.txt b/requirements.txt
index d2431b5c..ad70922d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,3 @@
 ply>= 3.4
-six>= 1.12.0
 packaging>=21.0
 Jinja2>= 3.0.3
diff --git a/stone/backends/obj_c_types.py b/stone/backends/obj_c_types.py
index ae485141..e11b4239 100644
--- a/stone/backends/obj_c_types.py
+++ b/stone/backends/obj_c_types.py
@@ -2,8 +2,6 @@
 import os
 import shutil
 
-import six
-
 from stone.backends.obj_c import (
     base_file_comment,
     comment_prefix,
@@ -915,7 +913,7 @@ def _determine_validator_type(self, data_type, value, has_default):
                          if data_type.min_length else 'nil'),
                         ('maxLength', '@({})'.format(data_type.max_length)
                          if data_type.max_length else 'nil'),
-                        ('pattern', '@"{}"'.format(six.ensure_str(pattern))
+                        ('pattern', '@"{}"'.format(str(pattern))
                          if pattern else 'nil'),
                     ]))
 
diff --git a/stone/backends/python_rsrc/stone_serializers.py b/stone/backends/python_rsrc/stone_serializers.py
index 7eac8506..0d03435d 100644
--- a/stone/backends/python_rsrc/stone_serializers.py
+++ b/stone/backends/python_rsrc/stone_serializers.py
@@ -20,8 +20,6 @@
 import re
 import time
 
-import six
-
 from stone.backends.python_rsrc import (
     stone_base as bb,
     stone_validators as bv,
@@ -658,7 +656,7 @@ def decode_union(self, data_type, obj):
         else:
             raise bv.ValidationError("expected string or object, got %s" %
                                      bv.generic_type_name(obj))
-        return data_type.definition(six.ensure_str(tag), val)
+        return data_type.definition(str(tag), val)
 
     def decode_union_dict(self, data_type, obj):
         if '.tag' not in obj:
@@ -785,7 +783,7 @@ def decode_union_old(self, data_type, obj):
         else:
             raise bv.ValidationError("expected string or object, got %s" %
                                      bv.generic_type_name(obj))
-        return data_type.definition(six.ensure_str(tag), val)
+        return data_type.definition(str(tag), val)
 
     def decode_struct_tree(self, data_type, obj):
         """
@@ -1003,45 +1001,7 @@ def _findall(text, substr):
 # Every 28 years the calendar repeats, except through century leap years
 # where it's 6 years. But only if you're using the Gregorian calendar. ;)
 def _strftime(dt, fmt):
-    try:
-        return dt.strftime(fmt)
-    except ValueError:
-        if not six.PY2 or dt.year > 1900:
-            raise
-
-    if _ILLEGAL_S.search(fmt):
-        raise TypeError("This strftime implementation does not handle %s")
-
-    year = dt.year
-
-    # For every non-leap year century, advance by 6 years to get into the
-    # 28-year repeat cycle
-    delta = 2000 - year
-    off = 6 * (delta // 100 + delta // 400)
-    year = year + off
-
-    # Move to around the year 2000
-    year = year + ((2000 - year) // 28) * 28
-    timetuple = dt.timetuple()
-    s1 = time.strftime(fmt, (year,) + timetuple[1:])
-    sites1 = _findall(s1, str(year))
-
-    s2 = time.strftime(fmt, (year + 28,) + timetuple[1:])
-    sites2 = _findall(s2, str(year + 28))
-
-    sites = []
-
-    for site in sites1:
-        if site in sites2:
-            sites.append(site)
-
-    s = s1
-    syear = '%4d' % (dt.year,)
-
-    for site in sites:
-        s = s[:site] + syear + s[site + 4:]
-
-    return s
+    return dt.strftime(fmt)
 
 
 try:
diff --git a/stone/backends/python_rsrc/stone_validators.py b/stone/backends/python_rsrc/stone_validators.py
index dc553ee8..3844baa9 100644
--- a/stone/backends/python_rsrc/stone_validators.py
+++ b/stone/backends/python_rsrc/stone_validators.py
@@ -14,8 +14,6 @@
 import re
 from abc import ABCMeta, abstractmethod
 
-import six
-
 _MYPY = False
 if _MYPY:
     import typing  # noqa: F401 # pylint: disable=import-error,unused-import,useless-suppression
@@ -328,17 +326,10 @@ def __init__(self, min_length=None, max_length=None, pattern=None):
     def validate(self, val):
         """
         A unicode string of the correct length and pattern will pass validation.
-        In PY2, we enforce that a str type must be valid utf-8, and a unicode
-        string will be returned.
         """
         if not isinstance(val, str):
             raise ValidationError("'%s' expected to be a string, got %s"
                                   % (get_value_string(val), generic_type_name(val)))
-        if not six.PY3 and isinstance(val, str):
-            try:
-                val = val.decode('utf-8')
-            except UnicodeDecodeError:
-                raise ValidationError("'%s' was not valid utf-8")
 
         if self.max_length is not None and len(val) > self.max_length:
             raise ValidationError("'%s' must be at most %d characters, got %d"
diff --git a/stone/backends/swift_types.py b/stone/backends/swift_types.py
index f07851ca..38393c16 100644
--- a/stone/backends/swift_types.py
+++ b/stone/backends/swift_types.py
@@ -2,7 +2,6 @@
 import os
 import shutil
 
-import six
 import jinja2
 import textwrap
 
@@ -304,7 +303,7 @@ def _determine_validator_type(self, data_type, value):
                 self._func_args([
                     ("minLength", data_type.min_length),
                     ("maxLength", data_type.max_length),
-                    ("pattern", '"{}"'.format(six.ensure_str(pat)) if pat else None),
+                    ("pattern", '"{}"'.format(str(pat)) if pat else None),
                 ])
             )
         else:
diff --git a/test/test_python_gen.py b/test/test_python_gen.py
index 1e8dfa35..69930064 100755
--- a/test/test_python_gen.py
+++ b/test/test_python_gen.py
@@ -10,8 +10,6 @@
 import sys
 import unittest
 
-import six
-
 import stone.backends.python_rsrc.stone_base as bb
 import stone.backends.python_rsrc.stone_serializers as ss
 import stone.backends.python_rsrc.stone_validators as bv
@@ -655,7 +653,7 @@ def __init__(self):
                 pass
 
         assert bv.type_name_with_module(Foo) == "test.test_python_gen.Foo"
-        assert bv.type_name_with_module(int) == "builtins.int" if six.PY3 else "__builtin__.int"
+        assert bv.type_name_with_module(int) == "builtins.int"
 
 
 test_spec = """\