diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0c893394..68074ac9 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,15 +11,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["pypy2", "pypy3", "2.7", "3.5", "3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["pypy-2.7", "pypy-3.8", "2.7", "3.7", "3.8", "3.9", "3.10"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         include:
           # Add new helper variables to existing jobs
-          - {python-version: "pypy2", toxenv: "pypy"}
-          - {python-version: "pypy3", toxenv: "pypy3"}
+          - {python-version: "pypy-2.7", toxenv: "pypy"}
+          - {python-version: "pypy-3.8", toxenv: "pypy3"}
           - {python-version: "2.7", toxenv: "py27"}
-          - {python-version: "3.5", toxenv: "py35"}
-          - {python-version: "3.6", toxenv: "py36"}
           - {python-version: "3.7", toxenv: "py37"}
           - {python-version: "3.8", toxenv: "py38"}
           - {python-version: "3.9", toxenv: "py39"}
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 83fc7f22..9d1e3cda 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,10 +1,12 @@
-0.4.5 In progress, unreleased
+0.4.5 Current release
+  * Catch a racy ValueError that could occur on exit.
   * Create README-hacking.md, for Colorama contributors.
   * Tweak some README unicode characters that don't render correctly on PyPI.
   * Fix some tests that were failing on some operating systems.
   * Add support for Python 3.9.
   * Add support for PyPy3.
-0.4.4 Current release
+  * Add support for pickling with the ``dill`` module.
+0.4.4
   * Re-org of README, to put the most insteresting parts near the top.
   * Added Linux makefile targets and Windows powershell scripts to
     automate bootstrapping a development environment, and automate the
diff --git a/MANIFEST.in b/MANIFEST.in
deleted file mode 100644
index 016aa76d..00000000
--- a/MANIFEST.in
+++ /dev/null
@@ -1,2 +0,0 @@
-include LICENSE.txt CHANGELOG.rst
-recursive-include demos *.py *.bat *.sh
diff --git a/Makefile b/Makefile
index a0b8987c..d56a3f79 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,6 @@ pip=$(virtualenv)/bin/pip
 syspython=python3.8
 python=$(virtualenv)/bin/python
 twine=$(virtualenv)/bin/twine
-version=$(shell $(python) setup.py --version)
 
 clean: ## Remove build artifacts, .pyc files, virtualenv
 	-rm -rf build dist MANIFEST colorama.egg-info $(virtualenv)
@@ -51,8 +50,7 @@ test: ## Run tests
 # build packages
 
 build: ## Build a release (sdist and wheel)
-	$(python) -m pip install --upgrade setuptools wheel
-	$(python) setup.py sdist bdist_wheel
+	$(python) -m build
 .PHONY: build
 
 test-release: build ## Test a built release
@@ -60,6 +58,5 @@ test-release: build ## Test a built release
 .PHONY: test-release
 
 release: ## Upload a built release
-	$(twine) upload dist/colorama-$(version)*{.whl,.tar.gz}
+	$(twine) upload dist/colorama-*
 .PHONY: release
-
diff --git a/README-hacking.md b/README-hacking.md
index b7c93961..21fab3e9 100644
--- a/README-hacking.md
+++ b/README-hacking.md
@@ -66,53 +66,75 @@ target.
 
 ## Release checklist
 
-TODO: Add the use of release candidate versions to this checklist.
-
 1. Check the CHANGELOG is updated with everything since the last release.
-2. Remove the '-pre' suffix from `__version__` in `colorama/__init.py__.py`.
+   Update CHANGELOG.rst with the new release version (move the comment for
+   "Current release")
+
+2. First we'll make a candidate release. Ensure  the '.rc1' suffix is
+   present on `__version__` in `colorama/__init.py__.py`.
+
 3. Run the tests locally on your preferred OS, just to save you from doing
    the following time-consuming steps while there are still obvious problems
    in the code:
 
-   * Windows: `./test.ps1`
-   * Linux: `make test`
+   * Windows:
+     * First allow powershell to execute scripts, see:
+       https://stackoverflow.com/a/32328091
+     * `powershell bootstrap.ps1`
+     * `powershell test.ps1`
+   * Linux:
+     * `make bootstrap`
+     * `make test`
 
 4. Verify you're all committed, merged to master, and pushed to origin (This
    triggers a CI build, which we'll check later on)
 
-5. Build the distributables (sdist and wheel), on either OS:
+5. Tag the current commit with the `__version__` from `colorama/__init__.py`.
+   We should start using
+   [annotated tags for releases](https://www.tartley.com/posts/til-git-annotated-tags/), so:
+
+       git tag -a -m "" $version
+       git push --follow-tags
+
+6. Build the distributables (sdist and wheel), on either OS:
 
     * Windows: `.\build.ps1`
     * Linux: `make build`
 
-6. Test the distributables on both OS. Whichever one you do 2nd will get an
+7. Test the distributables on both OS. Whichever one you do 2nd will get an
    HTTP 400 response on uploading to test.pypi.org, but outputs a message
    saying this is expected and carries on:
 
-   * Windows: `./clean.ps1 && .\bootstrap.ps1 && .\build.ps1 &&
-     .\test-release.ps1`
-   * Linux: `make clean bootstrap build test-release`
+   * Windows: `.\test-release.ps1`
+   * Linux: `make test-release`
 
-    (This currently only tests the wheel, but
-    [should soon test the sdist too](https://github.com/tartley/colorama/issues/286).)
+   (This currently only tests the wheel, but
+   [should soon test the sdist too](https://github.com/tartley/colorama/issues/286).)
 
-7. Check the [CI builds](https://github.com/tartley/colorama/actions/)
+8. Check the [CI builds](https://github.com/tartley/colorama/actions/)
    are complete and all passing.
 
-8. Upload the distributables to PyPI:
+9. Upload the distributables to PyPI:
 
    * On Windows: `.\release.ps1`
    * On Linux: `make release`
 
-   This [should soon tag the release for you](https://github.com/tartley/colorama/issues/282). Until then:
+10. Test by installing the candidate version from PyPI, and sanity check it with
+    'demo.sh', making sure this is running against the PyPI installation, not
+    local source.
 
-9. Tag the current commit with the `__version__` from `colorama/__init__.py`.
-   We should start using
-   [annotated tags for releases](https://www.tartley.com/posts/til-git-annotated-tags/), so:
+11. Maybe wait a day for anyone using pre-release installs to report any
+    problems?
 
-       git tag -a -m "" $version
-       git push --follow-tags
+12. Remove the '.rcX' suffix from `__version__` in
+    `colorama/__init__.py`.
+
+13. Repeat steps 5 to 10, for the actual (non-candidate) release.
+
+14. Bump the version number in `colorama/__init__.py`, and add a 'dev1'
+    suffix, eg:
+
+    `0.4.5dev1`
 
-10. Bump the version number in `colorama/__init__.py`, and add the '-pre'
-    suffix again, ready for the next release. Commit and push this (directly to
-    master is fine.)
+    so that any build artifacts created are clearly labelled as not a real
+    release. Commit and push this (directly to master is fine.)
diff --git a/README.rst b/README.rst
index 9a349ac1..fb0b75f3 100644
--- a/README.rst
+++ b/README.rst
@@ -30,7 +30,7 @@ If you find Colorama useful, please |donate| to the authors. Thank you!
 Installation
 ------------
 
-Tested on CPython 2.7, 3.5, 3.6, 3.7, 3.8, 3.9 and 3.10 and Pypy 2.7 and 3.6.
+Tested on CPython 2.7, 3.7, 3.8, 3.9 and 3.10 and Pypy 2.7 and 3.8.
 
 No requirements other than the standard library.
 
diff --git a/bootstrap.ps1 b/bootstrap.ps1
index 3260f8b4..53ba3314 100644
--- a/bootstrap.ps1
+++ b/bootstrap.ps1
@@ -1,4 +1,4 @@
-$syspython="python3.8.exe"
+$syspython="python.exe"
 $ve="$HOME\.virtualenvs\colorama"
 $bin="$ve\Scripts"
 
diff --git a/build.ps1 b/build.ps1
index a48e3578..bf26ebac 100644
--- a/build.ps1
+++ b/build.ps1
@@ -1,6 +1,5 @@
 $ve="$HOME\.virtualenvs\colorama"
 $bin="$ve\Scripts"
 
-& $bin\python.exe -m pip install --upgrade setuptools wheel
-& $bin\python.exe setup.py sdist bdist_wheel
-
+& $bin\python.exe -m pip install --upgrade build
+& $bin\python.exe -m build
diff --git a/clean.ps1 b/clean.ps1
index de9ba5ae..a2a59af3 100644
--- a/clean.ps1
+++ b/clean.ps1
@@ -1,4 +1,4 @@
-$syspython="python3.8.exe"
+$syspython="python.exe"
 $ve="$HOME\.virtualenvs\colorama"
 
 remove-item -r -fo * -I build,dist,MANIFEST,colorama.egg-info,$ve,sandbox
diff --git a/colorama/__init__.py b/colorama/__init__.py
index 641fd6fc..518ac808 100644
--- a/colorama/__init__.py
+++ b/colorama/__init__.py
@@ -3,4 +3,4 @@
 from .ansi import Fore, Back, Style, Cursor
 from .ansitowin32 import AnsiToWin32
 
-__version__ = '0.4.5-pre'
+__version__ = '0.4.6dev1'
diff --git a/colorama/ansitowin32.py b/colorama/ansitowin32.py
index 0cf7c397..20603111 100644
--- a/colorama/ansitowin32.py
+++ b/colorama/ansitowin32.py
@@ -37,6 +37,12 @@ def __enter__(self, *args, **kwargs):
     def __exit__(self, *args, **kwargs):
         return self.__wrapped.__exit__(*args, **kwargs)
 
+    def __setstate__(self, state):
+        self.__dict__ = state
+
+    def __getstate__(self):
+        return self.__dict__
+
     def write(self, text):
         self.__convertor.write(text)
 
@@ -57,7 +63,9 @@ def closed(self):
         stream = self.__wrapped
         try:
             return stream.closed
-        except AttributeError:
+        # AttributeError in the case that the stream doesn't support being closed
+        # ValueError for the case that the stream has already been detached when atexit runs
+        except (AttributeError, ValueError):
             return True
 
 
diff --git a/colorama/tests/ansitowin32_test.py b/colorama/tests/ansitowin32_test.py
index 380a99b7..91ca551f 100644
--- a/colorama/tests/ansitowin32_test.py
+++ b/colorama/tests/ansitowin32_test.py
@@ -1,5 +1,5 @@
 # Copyright Jonathan Hartley 2013. BSD 3-Clause license, see LICENSE file.
-from io import StringIO
+from io import StringIO, TextIOWrapper
 from unittest import TestCase, main
 try:
     from contextlib import ExitStack
@@ -46,6 +46,17 @@ def testProxyNoContextManager(self):
             with StreamWrapper(mockStream, mockConverter) as wrapper:
                 wrapper.write('hello')
 
+    def test_closed_shouldnt_raise_on_closed_stream(self):
+        stream = StringIO()
+        stream.close()
+        wrapper = StreamWrapper(stream, None)
+        self.assertEqual(wrapper.closed, True)
+
+    def test_closed_shouldnt_raise_on_detached_stream(self):
+        stream = TextIOWrapper(StringIO())
+        stream.detach()
+        wrapper = StreamWrapper(stream, None)
+        self.assertEqual(wrapper.closed, True)
 
 class AnsiToWin32Test(TestCase):
 
diff --git a/demos/demo.sh b/demos/demo.sh
index d8cbbcca..eb05b076 100644
--- a/demos/demo.sh
+++ b/demos/demo.sh
@@ -27,8 +27,9 @@ rm -f demo04.out
 # Demonstrate the difference between colorama initialized with wrapping on and off.
 python demo05.py
 
-# Demonstrate printing colored, random characters at random positions on the screen
-python demo06.py
+# Skip demo06
+# It is too visually disruptive,
+# making it hard to see whether any of the demos are working correctly.
 
 # Demonstrate cursor relative movement: UP, DOWN, FORWARD, and BACK in colorama.CURSOR
 python demo07.py
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..7f539788
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,64 @@
+[build-system]
+requires = [
+    "hatchling>=0.25.1",
+]
+build-backend = "hatchling.build"
+
+[project]
+name = "colorama"
+description = "Cross-platform colored terminal text."
+readme = "README.rst"
+license = "BSD-3-Clause"
+requires-python = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*, !=3.6.*"
+authors = [
+    { name = "Jonathan Hartley", email = "tartley@tartley.com" },
+]
+keywords = [
+    "ansi",
+    "color",
+    "colour",
+    "crossplatform",
+    "terminal",
+    "text",
+    "windows",
+    "xplatform",
+]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Environment :: Console",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: BSD License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 2",
+    "Programming Language :: Python :: 2.7",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+    "Topic :: Terminals",
+]
+dynamic = [
+    "version",
+]
+
+[project.urls]
+Homepage = "https://github.com/tartley/colorama"
+
+[tool.hatch.version]
+path = "colorama/__init__.py"
+
+[tool.hatch.build.targets.sdist]
+include = [
+    "/colorama",
+    "/demos",
+    "/CHANGELOG.rst",
+]
+
+[tool.hatch.build.targets.wheel]
+include = [
+    "/colorama/*",
+]
diff --git a/release.ps1 b/release.ps1
index ac4e2682..a9753bd9 100644
--- a/release.ps1
+++ b/release.ps1
@@ -1,7 +1,5 @@
 $ve="$HOME\.virtualenvs\colorama"
 $bin="$ve\Scripts"
-$version="$(& $bin\python.exe setup.py --version)"
 
 # Upload to PyPI.
-& $bin\twine.exe upload dist\colorama-$version*.tar.gz dist\colorama-$version-*.whl
-
+& $bin\twine.exe upload dist\colorama-*.tar.gz dist\colorama-*.whl
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 296bb90c..2f92fc49 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,4 +1,5 @@
 mock>=1.0.1;python_version<"3.3"
 twine>=3.1.1
 contextlib2;python_version<"3"
+build
 -e .
diff --git a/setup.cfg b/setup.cfg
deleted file mode 100644
index 2e9053c0..00000000
--- a/setup.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-[bdist_wheel]
-universal = 1
-
-[metadata]
-license_file = LICENSE.txt
diff --git a/setup.py b/setup.py
deleted file mode 100644
index 4221fe1b..00000000
--- a/setup.py
+++ /dev/null
@@ -1,68 +0,0 @@
-#!/usr/bin/env python
-# Copyright Jonathan Hartley 2013. BSD 3-Clause license, see LICENSE file.
-
-from __future__ import with_statement
-
-from io import open
-import os
-import re
-try:
-    from setuptools import setup
-except ImportError:
-    from distutils.core import setup
-
-
-NAME = 'colorama'
-
-
-def read_file(path, encoding='ascii'):
-    with open(os.path.join(os.path.dirname(__file__), path),
-              encoding=encoding) as fp:
-        return fp.read()
-
-def _get_version_match(content):
-    # Search for lines of the form: # __version__ = 'ver'
-    regex = r"^__version__ = ['\"]([^'\"]*)['\"]"
-    version_match = re.search(regex, content, re.M)
-    if version_match:
-        return version_match.group(1)
-    raise RuntimeError("Unable to find version string.")
-
-def get_version(path):
-    return _get_version_match(read_file(path))
-
-setup(
-    name=NAME,
-    version=get_version(os.path.join('colorama', '__init__.py')),
-    description='Cross-platform colored terminal text.',
-    long_description=read_file('README.rst'),
-    keywords='color colour terminal text ansi windows crossplatform xplatform',
-    author='Jonathan Hartley',
-    author_email='tartley@tartley.com',
-    maintainer='Arnon Yaari',
-    url='https://github.com/tartley/colorama',
-    license='BSD',
-    packages=[NAME],
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*',
-    # see classifiers https://pypi.org/pypi?%3Aaction=list_classifiers
-    classifiers=[
-        'Development Status :: 5 - Production/Stable',
-        'Environment :: Console',
-        'Intended Audience :: Developers',
-        'License :: OSI Approved :: BSD License',
-        'Operating System :: OS Independent',
-        'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
-        'Programming Language :: Python :: 3.8',
-        'Programming Language :: Python :: 3.9',
-        'Programming Language :: Python :: 3.10',
-        'Programming Language :: Python :: Implementation :: CPython',
-        'Programming Language :: Python :: Implementation :: PyPy',
-        'Topic :: Terminals',
-    ]
-)
diff --git a/test-release b/test-release
index 15812eff..e89d5dac 100644
--- a/test-release
+++ b/test-release
@@ -13,13 +13,12 @@
 # Exit on error
 set -eu -o pipefail
 
-syspython=python3.8
+syspython=python3
 bin="$HOME/.virtualenvs/colorama/bin"
-version=$($bin/python setup.py --version)
 sandbox=test-release-playground
 
 # Upload to the test PyPI.
-$bin/twine upload --repository testpypi dist/colorama-$version-* \
+$bin/twine upload --repository testpypi dist/colorama-* \
     || echo "  > Expect a 400 if package was already uploaded."
 
 # cd elsewhere so we cannot import from local source.
@@ -30,6 +29,11 @@ mkdir -p $sandbox
     # Create a temporary disposable virtualenv.
     $syspython -m venv --clear venv
 
+    # voodoo sleep. I saw the following install fail, due to expected version
+    # not being listed at test.pypi.org, but then a few seconds later, re-run
+    # manually. it worked fine.
+    sleep 5
+
     # Install the package we just uploaded.
     # (--extra-index-url for this project's requirements)
     venv/bin/python -m pip --quiet install --index-url https://test.pypi.org/simple --extra-index-url https://pypi.org/simple colorama==$version
@@ -40,4 +44,3 @@ mkdir -p $sandbox
 
 # Tidy up
 rm -rf $sandbox
-
diff --git a/test-release.ps1 b/test-release.ps1
index 19c6967b..e9af4a88 100644
--- a/test-release.ps1
+++ b/test-release.ps1
@@ -1,10 +1,9 @@
-$syspython="python3.8.exe"
+$syspython="python.exe"
 $ve="$HOME\.virtualenvs\colorama"
 $bin="$ve\Scripts"
-$version="$(& $bin\python.exe setup.py --version)"
 
 # Upload to the test PyPI.
-& $bin\twine.exe upload --repository testpypi dist\colorama-$version-*
+& $bin\twine.exe upload --repository testpypi dist\colorama-*
 if(!$?) {
     write-host "  > Expect a 400 if package was already uploaded"
 }
@@ -27,4 +26,3 @@ print(colorama.Fore.GREEN + ""OK Colorama "" + colorama.__version__ + "" from te
 "@
 
 cd ..
-
diff --git a/tox.ini b/tox.ini
index 721d811d..179745ac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,6 @@
 [tox]
-envlist = py27, py35, py36, py37, py38, py39, py310, pypy, pypy3
+isolated_build = true
+envlist = py27, py37, py38, py39, py310, pypy, pypy3
 
 [testenv]
 deps = py27,pypy: mock