diff --git a/requests_oauthlib/compliance_fixes/__init__.py b/requests_oauthlib/compliance_fixes/__init__.py
index 304ad3e..8815ea0 100644
--- a/requests_oauthlib/compliance_fixes/__init__.py
+++ b/requests_oauthlib/compliance_fixes/__init__.py
@@ -1,6 +1,4 @@
 # ruff: noqa: F401
-from __future__ import absolute_import
-
 from .facebook import facebook_compliance_fix
 from .fitbit import fitbit_compliance_fix
 from .slack import slack_compliance_fix
diff --git a/requests_oauthlib/compliance_fixes/douban.py b/requests_oauthlib/compliance_fixes/douban.py
index ecc57b0..c8b99c7 100644
--- a/requests_oauthlib/compliance_fixes/douban.py
+++ b/requests_oauthlib/compliance_fixes/douban.py
@@ -1,14 +1,12 @@
 import json
 
-from oauthlib.common import to_unicode
-
 
 def douban_compliance_fix(session):
     def fix_token_type(r):
         token = json.loads(r.text)
         token.setdefault("token_type", "Bearer")
         fixed_token = json.dumps(token)
-        r._content = to_unicode(fixed_token).encode("utf-8")
+        r._content = fixed_token.encode()
         return r
 
     session._client_default_token_placement = "query"
diff --git a/requests_oauthlib/compliance_fixes/ebay.py b/requests_oauthlib/compliance_fixes/ebay.py
index 4aa423b..ef33f39 100644
--- a/requests_oauthlib/compliance_fixes/ebay.py
+++ b/requests_oauthlib/compliance_fixes/ebay.py
@@ -1,5 +1,4 @@
 import json
-from oauthlib.common import to_unicode
 
 
 def ebay_compliance_fix(session):
@@ -13,7 +12,7 @@ def _compliance_fix(response):
         if token.get("token_type") in ["Application Access Token", "User Access Token"]:
             token["token_type"] = "Bearer"
             fixed_token = json.dumps(token)
-            response._content = to_unicode(fixed_token).encode("utf-8")
+            response._content = fixed_token.encode()
 
         return response
 
diff --git a/requests_oauthlib/compliance_fixes/facebook.py b/requests_oauthlib/compliance_fixes/facebook.py
index 90e7921..f44558a 100644
--- a/requests_oauthlib/compliance_fixes/facebook.py
+++ b/requests_oauthlib/compliance_fixes/facebook.py
@@ -1,11 +1,5 @@
 from json import dumps
-
-try:
-    from urlparse import parse_qsl
-except ImportError:
-    from urllib.parse import parse_qsl
-
-from oauthlib.common import to_unicode
+from urllib.parse import parse_qsl
 
 
 def facebook_compliance_fix(session):
@@ -26,7 +20,7 @@ def _compliance_fix(r):
         if expires is not None:
             token["expires_in"] = expires
         token["token_type"] = "Bearer"
-        r._content = to_unicode(dumps(token)).encode("UTF-8")
+        r._content = dumps(token).encode()
         return r
 
     session.register_compliance_hook("access_token_response", _compliance_fix)
diff --git a/requests_oauthlib/compliance_fixes/fitbit.py b/requests_oauthlib/compliance_fixes/fitbit.py
index 7e62702..aacc68b 100644
--- a/requests_oauthlib/compliance_fixes/fitbit.py
+++ b/requests_oauthlib/compliance_fixes/fitbit.py
@@ -8,8 +8,6 @@
 
 from json import loads, dumps
 
-from oauthlib.common import to_unicode
-
 
 def fitbit_compliance_fix(session):
     def _missing_error(r):
@@ -17,7 +15,7 @@ def _missing_error(r):
         if "errors" in token:
             # Set the error to the first one we have
             token["error"] = token["errors"][0]["errorType"]
-        r._content = to_unicode(dumps(token)).encode("UTF-8")
+        r._content = dumps(token).encode()
         return r
 
     session.register_compliance_hook("access_token_response", _missing_error)
diff --git a/requests_oauthlib/compliance_fixes/instagram.py b/requests_oauthlib/compliance_fixes/instagram.py
index 4e07fe0..7d5a2ad 100644
--- a/requests_oauthlib/compliance_fixes/instagram.py
+++ b/requests_oauthlib/compliance_fixes/instagram.py
@@ -1,7 +1,4 @@
-try:
-    from urlparse import urlparse, parse_qs
-except ImportError:
-    from urllib.parse import urlparse, parse_qs
+from urllib.parse import urlparse, parse_qs
 
 from oauthlib.common import add_params_to_uri
 
diff --git a/requests_oauthlib/compliance_fixes/mailchimp.py b/requests_oauthlib/compliance_fixes/mailchimp.py
index c69ce9f..0d60265 100644
--- a/requests_oauthlib/compliance_fixes/mailchimp.py
+++ b/requests_oauthlib/compliance_fixes/mailchimp.py
@@ -1,21 +1,19 @@
 import json
 
-from oauthlib.common import to_unicode
-
 
 def mailchimp_compliance_fix(session):
     def _null_scope(r):
         token = json.loads(r.text)
         if "scope" in token and token["scope"] is None:
             token.pop("scope")
-        r._content = to_unicode(json.dumps(token)).encode("utf-8")
+        r._content = json.dumps(token).encode()
         return r
 
     def _non_zero_expiration(r):
         token = json.loads(r.text)
         if "expires_in" in token and token["expires_in"] == 0:
             token["expires_in"] = 3600
-        r._content = to_unicode(json.dumps(token)).encode("utf-8")
+        r._content = json.dumps(token).encode()
         return r
 
     session.register_compliance_hook("access_token_response", _null_scope)
diff --git a/requests_oauthlib/compliance_fixes/plentymarkets.py b/requests_oauthlib/compliance_fixes/plentymarkets.py
index 9f605f0..859f056 100644
--- a/requests_oauthlib/compliance_fixes/plentymarkets.py
+++ b/requests_oauthlib/compliance_fixes/plentymarkets.py
@@ -1,8 +1,6 @@
 from json import dumps, loads
 import re
 
-from oauthlib.common import to_unicode
-
 
 def plentymarkets_compliance_fix(session):
     def _to_snake_case(n):
@@ -22,7 +20,7 @@ def _compliance_fix(r):
         for k, v in token.items():
             fixed_token[_to_snake_case(k)] = v
 
-        r._content = to_unicode(dumps(fixed_token)).encode("UTF-8")
+        r._content = dumps(fixed_token).encode()
         return r
 
     session.register_compliance_hook("access_token_response", _compliance_fix)
diff --git a/requests_oauthlib/compliance_fixes/slack.py b/requests_oauthlib/compliance_fixes/slack.py
index 3f574b0..9095a47 100644
--- a/requests_oauthlib/compliance_fixes/slack.py
+++ b/requests_oauthlib/compliance_fixes/slack.py
@@ -1,7 +1,4 @@
-try:
-    from urlparse import urlparse, parse_qs
-except ImportError:
-    from urllib.parse import urlparse, parse_qs
+from urllib.parse import urlparse, parse_qs
 
 from oauthlib.common import add_params_to_uri
 
diff --git a/requests_oauthlib/compliance_fixes/weibo.py b/requests_oauthlib/compliance_fixes/weibo.py
index 6733abe..f1623fd 100644
--- a/requests_oauthlib/compliance_fixes/weibo.py
+++ b/requests_oauthlib/compliance_fixes/weibo.py
@@ -1,13 +1,11 @@
 from json import loads, dumps
 
-from oauthlib.common import to_unicode
-
 
 def weibo_compliance_fix(session):
     def _missing_token_type(r):
         token = loads(r.text)
         token["token_type"] = "Bearer"
-        r._content = to_unicode(dumps(token)).encode("UTF-8")
+        r._content = dumps(token).encode()
         return r
 
     session._client.default_token_placement = "query"
diff --git a/requests_oauthlib/oauth1_auth.py b/requests_oauthlib/oauth1_auth.py
index cfbbd59..f8c0bd6 100644
--- a/requests_oauthlib/oauth1_auth.py
+++ b/requests_oauthlib/oauth1_auth.py
@@ -1,20 +1,15 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 import logging
 
 from oauthlib.common import extract_params
 from oauthlib.oauth1 import Client, SIGNATURE_HMAC, SIGNATURE_TYPE_AUTH_HEADER
 from oauthlib.oauth1 import SIGNATURE_TYPE_BODY
-from requests.compat import is_py3
 from requests.utils import to_native_string
 from requests.auth import AuthBase
 
 CONTENT_TYPE_FORM_URLENCODED = "application/x-www-form-urlencoded"
 CONTENT_TYPE_MULTI_PART = "multipart/form-data"
 
-if is_py3:
-    unicode = str
 
 log = logging.getLogger(__name__)
 
@@ -83,7 +78,7 @@ def __call__(self, r):
             or self.client.signature_type == SIGNATURE_TYPE_BODY
         ):
             content_type = CONTENT_TYPE_FORM_URLENCODED
-        if not isinstance(content_type, unicode):
+        if not isinstance(content_type, str):
             content_type = content_type.decode("utf-8")
 
         is_form_encoded = CONTENT_TYPE_FORM_URLENCODED in content_type
@@ -96,17 +91,17 @@ def __call__(self, r):
         if is_form_encoded:
             r.headers["Content-Type"] = CONTENT_TYPE_FORM_URLENCODED
             r.url, headers, r.body = self.client.sign(
-                unicode(r.url), unicode(r.method), r.body or "", r.headers
+                str(r.url), str(r.method), r.body or "", r.headers
             )
         elif self.force_include_body:
             # To allow custom clients to work on non form encoded bodies.
             r.url, headers, r.body = self.client.sign(
-                unicode(r.url), unicode(r.method), r.body or "", r.headers
+                str(r.url), str(r.method), r.body or "", r.headers
             )
         else:
             # Omit body data in the signing of non form-encoded requests
             r.url, headers, _ = self.client.sign(
-                unicode(r.url), unicode(r.method), None, r.headers
+                str(r.url), str(r.method), None, r.headers
             )
 
         r.prepare_headers(headers)
diff --git a/requests_oauthlib/oauth1_session.py b/requests_oauthlib/oauth1_session.py
index 2ca3034..7625c80 100644
--- a/requests_oauthlib/oauth1_session.py
+++ b/requests_oauthlib/oauth1_session.py
@@ -1,9 +1,4 @@
-from __future__ import unicode_literals
-
-try:
-    from urlparse import urlparse
-except ImportError:
-    from urllib.parse import urlparse
+from urllib.parse import urlparse
 
 import logging
 
diff --git a/requests_oauthlib/oauth2_auth.py b/requests_oauthlib/oauth2_auth.py
index b880f72..f19f52a 100644
--- a/requests_oauthlib/oauth2_auth.py
+++ b/requests_oauthlib/oauth2_auth.py
@@ -1,4 +1,3 @@
-from __future__ import unicode_literals
 from oauthlib.oauth2 import WebApplicationClient, InsecureTransportError
 from oauthlib.oauth2 import is_secure_transport
 from requests.auth import AuthBase
diff --git a/requests_oauthlib/oauth2_session.py b/requests_oauthlib/oauth2_session.py
index 11ea58f..93cc4d7 100644
--- a/requests_oauthlib/oauth2_session.py
+++ b/requests_oauthlib/oauth2_session.py
@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import logging
 
 from oauthlib.common import generate_token, urldecode
diff --git a/tests/test_compliance_fixes.py b/tests/test_compliance_fixes.py
index 63331af..c5166bd 100644
--- a/tests/test_compliance_fixes.py
+++ b/tests/test_compliance_fixes.py
@@ -1,14 +1,10 @@
-from __future__ import unicode_literals
 from unittest import TestCase
 
 import requests
 import requests_mock
 import time
 
-try:
-    from urlparse import urlparse, parse_qs
-except ImportError:
-    from urllib.parse import urlparse, parse_qs
+from urllib.parse import urlparse, parse_qs
 
 from oauthlib.oauth2.rfc6749.errors import InvalidGrantError
 from requests_oauthlib import OAuth2Session
diff --git a/tests/test_core.py b/tests/test_core.py
index 971ee6c..7ae5d08 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -1,5 +1,4 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 import requests
 import requests_oauthlib
 import oauthlib
@@ -7,10 +6,7 @@
 from io import StringIO
 import unittest
 
-try:
-    from unittest import mock
-except ImportError:
-    import mock
+from unittest import mock
 
 
 @mock.patch("oauthlib.oauth1.rfc5849.generate_timestamp")
diff --git a/tests/test_oauth1_session.py b/tests/test_oauth1_session.py
index 8d4ab87..b3c8c70 100644
--- a/tests/test_oauth1_session.py
+++ b/tests/test_oauth1_session.py
@@ -1,18 +1,12 @@
-from __future__ import unicode_literals, print_function
 import unittest
-import sys
 import requests
 from io import StringIO
+from unittest import mock
 
 from oauthlib.oauth1 import SIGNATURE_TYPE_QUERY, SIGNATURE_TYPE_BODY
 from oauthlib.oauth1 import SIGNATURE_RSA, SIGNATURE_PLAINTEXT
 from requests_oauthlib import OAuth1Session
 
-try:
-    from unittest import mock
-except ImportError:
-    import mock
-
 try:
     import cryptography
 except ImportError:
@@ -23,11 +17,6 @@
 except ImportError:
     jwt = None
 
-if sys.version[0] == "3":
-    unicode_type = str
-else:
-    unicode_type = unicode # noqa
-
 
 TEST_RSA_KEY = (
     "-----BEGIN RSA PRIVATE KEY-----\n"
@@ -165,8 +154,8 @@ def test_parse_response_url(self):
         self.assertEqual(resp["oauth_token"], "foo")
         self.assertEqual(resp["oauth_verifier"], "bar")
         for k, v in resp.items():
-            self.assertIsInstance(k, unicode_type)
-            self.assertIsInstance(v, unicode_type)
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
 
     def test_fetch_request_token(self):
         auth = OAuth1Session("foo")
@@ -174,8 +163,8 @@ def test_fetch_request_token(self):
         resp = auth.fetch_request_token("https://example.com/token")
         self.assertEqual(resp["oauth_token"], "foo")
         for k, v in resp.items():
-            self.assertIsInstance(k, unicode_type)
-            self.assertIsInstance(v, unicode_type)
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
 
     def test_fetch_request_token_with_optional_arguments(self):
         auth = OAuth1Session("foo")
@@ -185,8 +174,8 @@ def test_fetch_request_token_with_optional_arguments(self):
         )
         self.assertEqual(resp["oauth_token"], "foo")
         for k, v in resp.items():
-            self.assertIsInstance(k, unicode_type)
-            self.assertIsInstance(v, unicode_type)
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
 
     def test_fetch_access_token(self):
         auth = OAuth1Session("foo", verifier="bar")
@@ -194,8 +183,8 @@ def test_fetch_access_token(self):
         resp = auth.fetch_access_token("https://example.com/token")
         self.assertEqual(resp["oauth_token"], "foo")
         for k, v in resp.items():
-            self.assertIsInstance(k, unicode_type)
-            self.assertIsInstance(v, unicode_type)
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
 
     def test_fetch_access_token_with_optional_arguments(self):
         auth = OAuth1Session("foo", verifier="bar")
@@ -205,8 +194,8 @@ def test_fetch_access_token_with_optional_arguments(self):
         )
         self.assertEqual(resp["oauth_token"], "foo")
         for k, v in resp.items():
-            self.assertIsInstance(k, unicode_type)
-            self.assertIsInstance(v, unicode_type)
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
 
     def _test_fetch_access_token_raises_error(self, auth):
         """Assert that an error is being raised whenever there's no verifier
diff --git a/tests/test_oauth2_auth.py b/tests/test_oauth2_auth.py
index accb561..69ed6f6 100644
--- a/tests/test_oauth2_auth.py
+++ b/tests/test_oauth2_auth.py
@@ -1,4 +1,3 @@
-from __future__ import unicode_literals
 import unittest
 
 from oauthlib.oauth2 import WebApplicationClient, MobileApplicationClient
diff --git a/tests/test_oauth2_session.py b/tests/test_oauth2_session.py
index 0212712..7e3e63c 100644
--- a/tests/test_oauth2_session.py
+++ b/tests/test_oauth2_session.py
@@ -1,4 +1,3 @@
-from __future__ import unicode_literals
 import json
 import time
 import tempfile
@@ -8,10 +7,7 @@
 from copy import deepcopy
 from unittest import TestCase
 
-try:
-    from unittest import mock
-except ImportError:
-    import mock
+from unittest import mock
 
 from oauthlib.common import urlencode
 from oauthlib.oauth2 import TokenExpiredError, OAuth2Error