diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d1c9a59..8866812 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -18,3 +18,9 @@ repos:
     rev: 3.8.3
     hooks:
     - id: flake8
+
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v2.4.1
+    hooks:
+    - id: pyupgrade
+      args: [--py36-plus]
diff --git a/setup.py b/setup.py
index a3bcb27..d51ebda 100644
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import codecs
 import os
 
diff --git a/src/flask_uploads/extensions.py b/src/flask_uploads/extensions.py
index 52e0067..8e0f67b 100644
--- a/src/flask_uploads/extensions.py
+++ b/src/flask_uploads/extensions.py
@@ -1,4 +1,3 @@
-
 """Extension presets and extension configuration."""
 import os
 
@@ -63,7 +62,7 @@
 DEFAULTS = TEXT + DOCUMENTS + IMAGES + DATA
 
 
-class All(object):
+class All:
     """
     This type can be used to allow all extensions. There is a predefined
     instance named `ALL`.
@@ -77,7 +76,7 @@ def __contains__(self, item):
 ALL = All()
 
 
-class AllExcept(object):
+class AllExcept:
     """
     This can be used to allow all file types except certain ones. For example,
     to ban .exe and .iso files, pass::
diff --git a/src/flask_uploads/flask_uploads.py b/src/flask_uploads/flask_uploads.py
index 52730fc..492c049 100644
--- a/src/flask_uploads/flask_uploads.py
+++ b/src/flask_uploads/flask_uploads.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """
 flaskext.uploads
 ================
@@ -106,7 +105,7 @@ def configure_uploads(app, upload_sets):
         app.register_blueprint(uploads_mod)
 
 
-class UploadConfiguration(object):
+class UploadConfiguration:
     """
     This holds the configuration for a single `UploadSet`. The constructor's
     arguments are also the attributes.
@@ -134,7 +133,7 @@ def __eq__(self, other):
         return self.tuple == other.tuple
 
 
-class UploadSet(object):
+class UploadSet:
     """
     This represents a single set of uploaded files. Each upload set is
     independent of the others. This can be reused across multiple application
diff --git a/src/flask_uploads/test_helper.py b/src/flask_uploads/test_helper.py
index 6ce7781..c9eb657 100644
--- a/src/flask_uploads/test_helper.py
+++ b/src/flask_uploads/test_helper.py
@@ -5,15 +5,8 @@
     - it has to be importable
     - it can't be moved in the tests directory
 """
-import sys
-
 from werkzeug.datastructures import FileStorage
 
-if sys.version_info < (3,):  # python 2
-    string_types = basestring,  # noqa: F821
-else:  # python 3
-    string_types = str,
-
 
 class TestingFileStorage(FileStorage):
     """
@@ -51,7 +44,7 @@ def save(self, dst, buffer_size=16384):
         :param dst: The file to save to.
         :param buffer_size: Ignored.
         """
-        if isinstance(dst, string_types):
+        if isinstance(dst, str):
             self.saved = dst
         else:
             self.saved = dst.name
diff --git a/tests/test_flask_reuploaded.py b/tests/test_flask_reuploaded.py
index 3a29d0d..86da299 100644
--- a/tests/test_flask_reuploaded.py
+++ b/tests/test_flask_reuploaded.py
@@ -1,9 +1,7 @@
-# -*- coding: utf-8 -*-
 """
 :copyright: 2010 Matthew "LeafStorm" Frazier
 :license:   MIT/X11, see LICENSE for details
 """
-from __future__ import with_statement
 
 import os
 import os.path
@@ -22,7 +20,7 @@
 from flask_uploads import lowercase_ext
 
 
-class TestMiscellaneous(object):
+class TestMiscellaneous:
     def test_tfs(self):
         tfs = TestingFileStorage(filename='foo.bar')
         assert tfs.filename == 'foo.bar'
@@ -68,7 +66,7 @@ def test_custom_iterables(self):
 Config = UploadConfiguration
 
 
-class TestConfiguration(object):
+class TestConfiguration:
     def setup(self):
         self.app = Flask(__name__)
 
@@ -157,7 +155,7 @@ def test_default_destination_callable(self):
         assert photo_conf == Config('/mnt/photos', 'http://localhost:6002/')
 
 
-class TestPreconditions(object):
+class TestPreconditions:
     def test_filenames(self):
         uset = UploadSet('files')
         uset._config = Config('/uploads')
@@ -178,7 +176,7 @@ def test_default_extensions(self):
             assert uset.extension_allowed(ext) is result
 
 
-class TestSaving(object):
+class TestSaving:
     def setup(self):
         self.old_makedirs = os.makedirs
         os.makedirs = lambda v: None
@@ -260,7 +258,7 @@ def test_storage_is_not_a_werkzeug_datastructure(self):
             uset.save(non_storage)
 
 
-class TestConflictResolution(object):
+class TestConflictResolution:
     def setup(self):
         self.extant_files = []
         self.old_exists = os.path.exists
@@ -311,7 +309,7 @@ def test_conflict_without_extension(self):
         assert res == 'foo_1'
 
 
-class TestPathsAndURLs(object):
+class TestPathsAndURLs:
     def test_path(self):
         uset = UploadSet('files')
         uset._config = Config('/uploads')