diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3904fda6..306700fc 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,6 +14,7 @@ jobs:
           - "3.7"
           - "3.8"
           - "3.9"
+          - "3.10.0-rc.2"
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python-version }}
@@ -33,6 +34,8 @@ jobs:
         run: |
           pip install poetry
           poetry config virtualenvs.in-project true
+      - name: Python 3.10 workaround
+        run: poetry config experimental.new-installer false
       - name: Install dependencies
         run: poetry install
       - name: Run pytest
diff --git a/poetry.lock b/poetry.lock
index efbb5574..0097adbd 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -6,14 +6,6 @@ category = "dev"
 optional = false
 python-versions = "*"
 
-[[package]]
-name = "appdirs"
-version = "1.4.4"
-description = "A small Python module for determining appropriate platform-specific dirs, e.g. a \"user data dir\"."
-category = "dev"
-optional = false
-python-versions = "*"
-
 [[package]]
 name = "atomicwrites"
 version = "1.4.0"
@@ -49,26 +41,32 @@ pytz = ">=2015.7"
 
 [[package]]
 name = "black"
-version = "20.8b1"
+version = "21.9b0"
 description = "The uncompromising code formatter."
 category = "dev"
 optional = false
-python-versions = ">=3.6"
+python-versions = ">=3.6.2"
 
 [package.dependencies]
-appdirs = "*"
 click = ">=7.1.2"
 dataclasses = {version = ">=0.6", markers = "python_version < \"3.7\""}
 mypy-extensions = ">=0.4.3"
-pathspec = ">=0.6,<1"
+pathspec = ">=0.9.0,<1"
+platformdirs = ">=2"
 regex = ">=2020.1.8"
-toml = ">=0.10.1"
-typed-ast = ">=1.4.0"
-typing-extensions = ">=3.7.4"
+tomli = ">=0.2.6,<2.0.0"
+typed-ast = {version = ">=1.4.2", markers = "python_version < \"3.8\""}
+typing-extensions = [
+    {version = ">=3.10.0.0", markers = "python_version < \"3.10\""},
+    {version = "!=3.10.0.1", markers = "python_version >= \"3.10\""},
+]
 
 [package.extras]
 colorama = ["colorama (>=0.4.3)"]
-d = ["aiohttp (>=3.3.2)", "aiohttp-cors"]
+d = ["aiohttp (>=3.6.0)", "aiohttp-cors (>=0.4.0)"]
+jupyter = ["ipython (>=7.8.0)", "tokenize-rt (>=3.2.0)"]
+python2 = ["typed-ast (>=1.4.2)"]
+uvloop = ["uvloop (>=0.15.2)"]
 
 [[package]]
 name = "certifi"
@@ -221,16 +219,17 @@ python-versions = "*"
 
 [[package]]
 name = "isort"
-version = "5.8.0"
+version = "5.9.3"
 description = "A Python utility / library to sort Python imports."
 category = "dev"
 optional = false
-python-versions = ">=3.6,<4.0"
+python-versions = ">=3.6.1,<4.0"
 
 [package.extras]
 pipfile_deprecated_finder = ["pipreqs", "requirementslib"]
 requirements_deprecated_finder = ["pipreqs", "pip-api"]
 colors = ["colorama (>=0.4.3,<0.5.0)"]
+plugins = ["setuptools"]
 
 [[package]]
 name = "jinja2"
@@ -293,6 +292,18 @@ category = "dev"
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.7"
 
+[[package]]
+name = "platformdirs"
+version = "2.3.0"
+description = "A small Python module for determining appropriate platform-specific dirs, e.g. a \"user data dir\"."
+category = "dev"
+optional = false
+python-versions = ">=3.6"
+
+[package.extras]
+docs = ["Sphinx (>=4)", "furo (>=2021.7.5b38)", "proselint (>=0.10.2)", "sphinx-autodoc-typehints (>=1.12)"]
+test = ["appdirs (==1.4.4)", "pytest (>=6)", "pytest-cov (>=2.7)", "pytest-mock (>=3.6)"]
+
 [[package]]
 name = "pluggy"
 version = "1.0.0"
@@ -608,6 +619,14 @@ category = "dev"
 optional = false
 python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
 
+[[package]]
+name = "tomli"
+version = "1.2.1"
+description = "A lil' TOML parser"
+category = "dev"
+optional = false
+python-versions = ">=3.6"
+
 [[package]]
 name = "tornado"
 version = "6.1"
@@ -659,18 +678,14 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytes
 
 [metadata]
 lock-version = "1.1"
-python-versions = "^3.6"
-content-hash = "6e555d8be0460f34e0121d5becbb388833be3e507266196ef2f1414642733680"
+python-versions = "^3.6.2"
+content-hash = "adb42c953d339e45681bd2ea231b5afdb3e72f09cedc46af05d355b67a0a36dd"
 
 [metadata.files]
 alabaster = [
     {file = "alabaster-0.7.12-py2.py3-none-any.whl", hash = "sha256:446438bdcca0e05bd45ea2de1668c1d9b032e1a9154c2c259092d77031ddd359"},
     {file = "alabaster-0.7.12.tar.gz", hash = "sha256:a661d72d58e6ea8a57f7a86e37d86716863ee5e92788398526d58b26a4e4dc02"},
 ]
-appdirs = [
-    {file = "appdirs-1.4.4-py2.py3-none-any.whl", hash = "sha256:a841dacd6b99318a741b166adb07e19ee71a274450e68237b4650ca1055ab128"},
-    {file = "appdirs-1.4.4.tar.gz", hash = "sha256:7d5d0167b2b1ba821647616af46a749d1c653740dd0d2415100fe26e27afdf41"},
-]
 atomicwrites = [
     {file = "atomicwrites-1.4.0-py2.py3-none-any.whl", hash = "sha256:6d1784dea7c0c8d4a5172b6c620f40b6e4cbfdf96d783691f2e1302a7b88e197"},
     {file = "atomicwrites-1.4.0.tar.gz", hash = "sha256:ae70396ad1a434f9c7046fd2dd196fc04b12f9e91ffb859164193be8b6168a7a"},
@@ -684,7 +699,8 @@ babel = [
     {file = "Babel-2.9.1.tar.gz", hash = "sha256:bc0c176f9f6a994582230df350aa6e05ba2ebe4b3ac317eab29d9be5d2768da0"},
 ]
 black = [
-    {file = "black-20.8b1.tar.gz", hash = "sha256:1c02557aa099101b9d21496f8a914e9ed2222ef70336404eeeac8edba836fbea"},
+    {file = "black-21.9b0-py3-none-any.whl", hash = "sha256:380f1b5da05e5a1429225676655dddb96f5ae8c75bdf91e53d798871b902a115"},
+    {file = "black-21.9b0.tar.gz", hash = "sha256:7de4cfc7eb6b710de325712d40125689101d21d25283eed7e9998722cf10eb91"},
 ]
 certifi = [
     {file = "certifi-2021.5.30-py2.py3-none-any.whl", hash = "sha256:50b1e4f8446b06f41be7dd6338db18e0990601dce795c2b1686458aa7e8fa7d8"},
@@ -852,8 +868,8 @@ iniconfig = [
     {file = "iniconfig-1.1.1.tar.gz", hash = "sha256:bc3af051d7d14b2ee5ef9969666def0cd1a000e121eaea580d4a313df4b37f32"},
 ]
 isort = [
-    {file = "isort-5.8.0-py3-none-any.whl", hash = "sha256:2bb1680aad211e3c9944dbce1d4ba09a989f04e238296c87fe2139faa26d655d"},
-    {file = "isort-5.8.0.tar.gz", hash = "sha256:0a943902919f65c5684ac4e0154b1ad4fac6dcaa5d9f3426b732f1c8b5419be6"},
+    {file = "isort-5.9.3-py3-none-any.whl", hash = "sha256:e17d6e2b81095c9db0a03a8025a957f334d6ea30b26f9ec70805411e5c7c81f2"},
+    {file = "isort-5.9.3.tar.gz", hash = "sha256:9c2ea1e62d871267b78307fe511c0838ba0da28698c5732d54e2790bf3ba9899"},
 ]
 jinja2 = [
     {file = "Jinja2-3.0.1-py3-none-any.whl", hash = "sha256:1f06f2da51e7b56b8f238affdd6b4e2c61e39598a378cc49345bc1bd42a978a4"},
@@ -909,6 +925,12 @@ packaging = [
 pathspec = [
     {file = "pathspec-0.9.0-py2.py3-none-any.whl", hash = "sha256:7d15c4ddb0b5c802d161efc417ec1a2558ea2653c2e8ad9c19098201dc1c993a"},
     {file = "pathspec-0.9.0.tar.gz", hash = "sha256:e564499435a2673d586f6b2130bb5b95f04a3ba06f81b8f895b651a3c76aabb1"},
+
+]
+platformdirs = [
+    {file = "platformdirs-2.3.0-py3-none-any.whl", hash = "sha256:8003ac87717ae2c7ee1ea5a84a1a61e87f3fbd16eb5aadba194ea30a9019f648"},
+    {file = "platformdirs-2.3.0.tar.gz", hash = "sha256:15b056538719b1c94bdaccb29e5f81879c7f7f0f4a153f46086d155dffcd4f0f"},
+
 ]
 pluggy = [
     {file = "pluggy-1.0.0-py2.py3-none-any.whl", hash = "sha256:74134bbf457f031a36d68416e1509f34bd5ccc019f0bcc952c7b909d06b37bd3"},
@@ -1048,6 +1070,10 @@ toml = [
     {file = "toml-0.10.2-py2.py3-none-any.whl", hash = "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b"},
     {file = "toml-0.10.2.tar.gz", hash = "sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f"},
 ]
+tomli = [
+    {file = "tomli-1.2.1-py3-none-any.whl", hash = "sha256:8dd0e9524d6f386271a36b41dbf6c57d8e32fd96fd22b6584679dc569d20899f"},
+    {file = "tomli-1.2.1.tar.gz", hash = "sha256:a5b75cb6f3968abb47af1b40c1819dc519ea82bcc065776a866e8d74c5ca9442"},
+]
 tornado = [
     {file = "tornado-6.1-cp35-cp35m-macosx_10_9_x86_64.whl", hash = "sha256:d371e811d6b156d82aa5f9a4e08b58debf97c302a35714f6f45e35139c332e32"},
     {file = "tornado-6.1-cp35-cp35m-manylinux1_i686.whl", hash = "sha256:0d321a39c36e5f2c4ff12b4ed58d41390460f798422c4504e09eb5678e09998c"},
diff --git a/pyproject.toml b/pyproject.toml
index 141ece4c..3e947f90 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,14 +38,14 @@ jwkconv = "cryptojwt.tools.keyconv:main"
 jwtpeek = "cryptojwt.tools.jwtpeek:main"
 
 [tool.poetry.dependencies]
-python = "^3.6"
+python = "^3.6.2"
 cryptography = "^3.4.6"
 requests = "^2.25.1"
 readerwriterlock = "^1.0.9"
 
 [tool.poetry.dev-dependencies]
 alabaster = "^0.7.12"
-black = "^20.8b1"
+black = "^21.5b1"
 isort = "^5.6.4"
 pytest = "^6.1.2"
 pytest-black = "^0.3.12"
diff --git a/src/cryptojwt/key_issuer.py b/src/cryptojwt/key_issuer.py
index 42a262ee..2b3b4b53 100755
--- a/src/cryptojwt/key_issuer.py
+++ b/src/cryptojwt/key_issuer.py
@@ -21,7 +21,7 @@
 
 
 class KeyIssuer(object):
-    """ A key issuer instance contains a number of KeyBundles. """
+    """A key issuer instance contains a number of KeyBundles."""
 
     params = {
         "ca_certs": None,
diff --git a/src/cryptojwt/key_jar.py b/src/cryptojwt/key_jar.py
index b4610907..2d6f7f96 100755
--- a/src/cryptojwt/key_jar.py
+++ b/src/cryptojwt/key_jar.py
@@ -22,7 +22,7 @@
 
 
 class KeyJar(object):
-    """ A keyjar contains a number of KeyBundles sorted by owner/issuer """
+    """A keyjar contains a number of KeyBundles sorted by owner/issuer"""
 
     def __init__(
         self,
diff --git a/src/cryptojwt/serialize/item.py b/src/cryptojwt/serialize/item.py
index 206eb7de..d27b4350 100644
--- a/src/cryptojwt/serialize/item.py
+++ b/src/cryptojwt/serialize/item.py
@@ -6,11 +6,11 @@
 class KeyIssuer:
     @staticmethod
     def serialize(item: key_issuer.KeyIssuer) -> str:
-        """ Convert from KeyIssuer to JSON """
+        """Convert from KeyIssuer to JSON"""
         return json.dumps(item.dump(exclude_attributes=["keybundle_cls"]))
 
     def deserialize(self, spec: str) -> key_issuer.KeyIssuer:
-        """ Convert from JSON to KeyIssuer """
+        """Convert from JSON to KeyIssuer"""
         _dict = json.loads(spec)
         issuer = key_issuer.KeyIssuer().load(_dict)
         return issuer
diff --git a/src/cryptojwt/tools/keyconv.py b/src/cryptojwt/tools/keyconv.py
index 83f0b2d0..a5b27112 100644
--- a/src/cryptojwt/tools/keyconv.py
+++ b/src/cryptojwt/tools/keyconv.py
@@ -174,7 +174,7 @@ def output_bytes(data: bytes, binary: bool = False, filename: Optional[str] = No
 
 
 def main():
-    """ Main function"""
+    """Main function"""
     parser = argparse.ArgumentParser(description="JWK Conversion Utility")
 
     parser.add_argument("--kid", dest="kid", metavar="key_id", help="Key ID")
diff --git a/src/cryptojwt/tools/keygen.py b/src/cryptojwt/tools/keygen.py
index 06776167..7ae8e304 100644
--- a/src/cryptojwt/tools/keygen.py
+++ b/src/cryptojwt/tools/keygen.py
@@ -19,7 +19,7 @@
 
 
 def main():
-    """ Main function"""
+    """Main function"""
     parser = argparse.ArgumentParser(description="JSON Web Key (JWK) Generator")
 
     parser.add_argument("--kty", dest="kty", metavar="type", help="Key type", required=True)
diff --git a/tests/test_04_key_jar.py b/tests/test_04_key_jar.py
index 1a472b6a..1c470783 100755
--- a/tests/test_04_key_jar.py
+++ b/tests/test_04_key_jar.py
@@ -688,7 +688,7 @@ def setup(self):
         self.sjwt_b = _jws.sign_compact([sig_key])
 
     def test_no_kid_multiple_keys(self):
-        """ This is extremely strict """
+        """This is extremely strict"""
         _jwt = factory(self.sjwt_a)
         # remove kid reference
         _jwt.jwt.headers["kid"] = ""