diff --git a/debtcollector/_utils.py b/debtcollector/_utils.py
index 80bada7..6e4ff08 100644
--- a/debtcollector/_utils.py
+++ b/debtcollector/_utils.py
@@ -19,8 +19,6 @@ import inspect
 import types
 import warnings
 
-import six
-
 try:
     _TYPE_TYPE = types.TypeType
 except AttributeError:
@@ -91,14 +89,7 @@ def generate_message(prefix, postfix=None, message=None,
 
 def get_assigned(decorator):
     """Helper to fix/workaround https://bugs.python.org/issue3445"""
-    if six.PY3:
-        return functools.WRAPPER_ASSIGNMENTS
-    else:
-        assigned = []
-        for attr_name in functools.WRAPPER_ASSIGNMENTS:
-            if hasattr(decorator, attr_name):
-                assigned.append(attr_name)
-        return tuple(assigned)
+    return functools.WRAPPER_ASSIGNMENTS
 
 
 def get_class_name(obj, fully_qualified=True):
@@ -108,7 +99,7 @@ def get_class_name(obj, fully_qualified=True):
     Else, fully qualified name of the type of the object is returned.
     For builtin types, just name is returned.
     """
-    if not isinstance(obj, six.class_types):
+    if not isinstance(obj, type):
         obj = type(obj)
     try:
         built_in = obj.__module__ in _BUILTIN_MODULES
@@ -129,7 +120,7 @@ def get_method_self(method):
     if not inspect.ismethod(method):
         return None
     try:
-        return six.get_method_self(method)
+        return getattr(method, '__self__')
     except AttributeError:
         return None
 
@@ -142,7 +133,7 @@ def get_callable_name(function):
     method_self = get_method_self(function)
     if method_self is not None:
         # This is a bound method.
-        if isinstance(method_self, six.class_types):
+        if isinstance(method_self, type):
             # This is a bound class method.
             im_class = method_self
         else:
diff --git a/debtcollector/moves.py b/debtcollector/moves.py
index 27c10e2..519a9b3 100644
--- a/debtcollector/moves.py
+++ b/debtcollector/moves.py
@@ -14,9 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import functools
 import inspect
 
-import six
 import wrapt
 
 from debtcollector import _utils
@@ -76,7 +76,7 @@ def moved_function(new_func, old_func_name, old_module_name,
                                           message=message, version=version,
                                           removal_version=removal_version)
 
-    @six.wraps(new_func, assigned=_utils.get_assigned(new_func))
+    @functools.wraps(new_func, assigned=_utils.get_assigned(new_func))
     def old_new_func(*args, **kwargs):
         _utils.deprecation(out_message, stacklevel=stacklevel,
                            category=category)
@@ -183,7 +183,7 @@ def moved_class(new_class, old_class_name, old_module_name,
 
     def decorator(f):
 
-        @six.wraps(f, assigned=_utils.get_assigned(f))
+        @functools.wraps(f, assigned=_utils.get_assigned(f))
         def wrapper(self, *args, **kwargs):
             _utils.deprecation(out_message, stacklevel=stacklevel,
                                category=category)
diff --git a/debtcollector/removals.py b/debtcollector/removals.py
index aa416ed..ea44c67 100644
--- a/debtcollector/removals.py
+++ b/debtcollector/removals.py
@@ -15,7 +15,6 @@
 import functools
 import inspect
 
-import six
 import wrapt
 
 from debtcollector import _utils
@@ -270,7 +269,7 @@ def removed_class(cls_name, replacement=None, message=None,
 
     def _wrap_it(old_init, out_message):
 
-        @six.wraps(old_init, assigned=_utils.get_assigned(old_init))
+        @functools.wraps(old_init, assigned=_utils.get_assigned(old_init))
         def new_init(self, *args, **kwargs):
             _utils.deprecation(out_message, stacklevel=stacklevel,
                                category=category)
@@ -315,7 +314,7 @@ def removed_module(module, replacement=None, message=None,
     """
     if inspect.ismodule(module):
         module_name = _get_qualified_name(module)
-    elif isinstance(module, six.string_types):
+    elif isinstance(module, str):
         module_name = module
     else:
         _qual, type_name = _utils.get_qualified_name(type(module))
diff --git a/requirements.txt b/requirements.txt
index ae353a3..8e9f61c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,5 +4,4 @@
 
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 importlib_metadata>=1.7.0;python_version<'3.8' # Apache-2.0
-six>=1.10.0 # MIT
 wrapt>=1.7.0 # BSD License