diff --git a/.coveragerc b/.coveragerc
index ed5b25a..f52803f 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -4,6 +4,8 @@ source_pkgs = icrs.releaser
 # Perhaps this obsoletes the source section in [paths]?
 relative_files = True
 branch = true
+parallel = true
+concurrency = thread
 
 [report]
 # Coverage is run on Linux under cPython 2 and 3,
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 8372cd8..f2eca3e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -11,7 +11,7 @@ jobs:
   test:
     strategy:
       matrix:
-        python-version: ['3.8', '3.9', '3.10', 'pypy-3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', 'pypy-3.10', '3.11', '3.12']
 
     runs-on: ubuntu-latest
     steps:
@@ -29,8 +29,10 @@ jobs:
         python -m pip install -U -e ".[test,docs]"
     - name: Test
       run: |
-        coverage run -m zope.testrunner --test-path=src  --auto-color --auto-progress
-        coverage run -a -m sphinx -b doctest -d docs/_build/doctrees docs docs/_build/doctests
+        coverage run -m zope.testrunner --package-path src/icrs/releaser icrs.releaser  --auto-color --auto-progress
+        coverage run -m sphinx -b doctest -d docs/_build/doctrees docs docs/_build/doctests
+        coverage combine
+        coverage report
     - name: Submit to Coveralls
       # This is a container action, which only runs on Linux.
       uses: AndreMiras/coveralls-python-action@develop
diff --git a/CHANGES.rst b/CHANGES.rst
index 0e9fedc..9dd613b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,9 +6,13 @@
 ==================
 
 - Add support for Python 3.11 and 3.12.
-- Depend on newer ``zest.releaser >. 9.1.1``.
-- Remove dependency on setuptools; now uses the poorly desgined
+- Drop support for Python 3.8. The minimum supported version is now 3.9.
+- Depend on newer ``zest.releaser >= 9.1.1``.
+- Remove dependency on setuptools; now uses the so-called
   "native" namespace packages.
+- Add a new release check that forbids having development dependencies
+  (e.g., "icrs.releaser >= 3.0.dev0" would be forbidden). This only
+  works for ``setuptools`` projects that have dependencies listed in setup.py.
 
 
 1.1.0 (2022-03-03)
diff --git a/MANIFEST.in b/MANIFEST.in
index 3de5144..b5d4fb3 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -18,4 +18,6 @@ recursive-include docs *.py
 recursive-include docs *.rst
 recursive-include docs *.css
 recursive-include docs Makefile
+
 recursive-include src *.zcml
+recursive-include src *.txt
diff --git a/setup.py b/setup.py
index 4d1e3c6..99a27a6 100755
--- a/setup.py
+++ b/setup.py
@@ -5,10 +5,11 @@
 from setuptools import find_namespace_packages
 
 
-version = '1.1.1.dev0'
+version = '1.2.0'
 
 entry_points = {
     'zest.releaser.prereleaser.before': [
+        'dev_middle = icrs.releaser.devremover:prereleaser_before',
         # XXX: This only works doing fullrelease
         'rm_cflags = icrs.releaser.removecflags:prereleaser_before',
     ],
@@ -16,7 +17,7 @@
         'version_next = icrs.releaser.versionreplacer:prereleaser_middle',
         # XXX: This only works doing fullrelease
         'scm_middle = icrs.releaser.setuptools_scm_versionfixer:prereleaser_middle',
-        # XXX: Add check for .dev.
+
     ],
     'console_scripts': [
         'icrs_release = icrs.releaser.fullrelease:main',
@@ -50,7 +51,6 @@ def _read(fname):
         'Natural Language :: English',
         'Operating System :: OS Independent',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
         'Programming Language :: Python :: 3.10',
         'Programming Language :: Python :: 3.11',
@@ -64,7 +64,6 @@ def _read(fname):
     package_dir={'': 'src'},
     namespace_packages=['icrs'],
     install_requires=[
-        'setuptools_scm',
         'zest.releaser >= 9.1.1',
     ],
     entry_points=entry_points,
@@ -80,5 +79,5 @@ def _read(fname):
             'zest.releaser[recommended]',
         ],
     },
-    python_requires=">=3.8",
+    python_requires=">=3.9",
 )
diff --git a/src/icrs/releaser/devremover.py b/src/icrs/releaser/devremover.py
new file mode 100644
index 0000000..da29614
--- /dev/null
+++ b/src/icrs/releaser/devremover.py
@@ -0,0 +1,86 @@
+# -*- coding: utf-8 -*-
+"""
+See `prereleaser_before`.
+
+"""
+
+import re
+import sys
+
+from pathlib import Path
+
+class DevelopmentDependency(Exception):
+    """
+    Raised when a development dependency is detected.
+    """
+
+# An expression that matches dependency specification lines that have
+# ".dev" versions.
+#
+# TODO: The ``packaging`` library
+# (https://packaging.pypa.io/en/stable/index.html) has support to
+# actually parse all of these complicated specifiers; the problem is
+# extracting which lines need to be parsed like that. We're just
+# matching the entire file
+_SETUP_PY_DEV_REQUIREMENT_MATCHER = re.compile(
+    # open single or double quote
+    br"['\"]"
+    # one or more alphanumeric characters, underscores, periods
+    # commas, spaces or square brackets (for extras)
+    # and zero or more spaces
+    br"[\w.,\[\] ]+\s*"
+    # followed by an operator.
+    # (recall that 'foo < 3, >2, !=2.1' is valid syntax; the clauses can come in
+    # any order). See https://peps.python.org/pep-0508/
+    br"[>=<!~]"
+    # followed by any number of characters of any sort, but with at least one number.
+    br".*\d+.*"
+    # followed by the ".dev" sequence
+    br"\.dev"
+    # followed by any number of characters
+    br".*"
+    # ended with the closing string quote
+    # (if we wanted to be super smart, we would use a capture group to match
+    # the actual opening quote)
+    br"['\"]"
+)
+
+def prereleaser_before(data):
+    """
+    Checks for development dependencies and raise an error
+    if found.
+
+    A non-released dependency is something in setup.py that has a version number
+    containing ".dev". An exception is raised if this is found.
+
+    This is a "prereleaser before" hook so that it runs before anything
+    tries to commit to the project (e.g., to update the version number).
+
+    .. todo::
+
+       This only supports traditional setuptools-style
+       projects and only supports setup.py. Ideally, it would
+       support pyproject.toml, setup.cfg and generic build backends.
+       We'd need to be able to get the project metadata (``.egg-info`` in setuptools,
+       or part of the records recorded in the wheel file) to make that
+       work reliably, though, and I'm not sure how to do that.
+    """
+    report = data.get('icrs.releaser:report', print)
+    report('Checking for the existence of development dependencies.')
+    root_dir = Path(data['reporoot'])
+
+    for p in (
+        root_dir / 'setup.py',
+    ):
+        if not p.is_file():
+            report('Project file', p, "does not exist; not checking for development deps.",
+                   file=sys.stderr)
+            continue
+
+        contents = p.read_bytes()
+        if (match := _SETUP_PY_DEV_REQUIREMENT_MATCHER.search(contents)):
+            raise DevelopmentDependency(
+                "Project file %s had development dependency: %s" % (
+                    p, match.group().decode('utf-8', errors='ignore')
+                )
+            )
diff --git a/src/icrs/releaser/tests/example_setup.txt b/src/icrs/releaser/tests/example_setup.txt
new file mode 100755
index 0000000..4be9347
--- /dev/null
+++ b/src/icrs/releaser/tests/example_setup.txt
@@ -0,0 +1,85 @@
+# pragma: no cover
+# Copyright 2020 NextThought
+# Released under the terms of the LICENSE file.
+import codecs
+from setuptools import setup
+from setuptools import find_namespace_packages
+
+
+version = '1.1.1.dev0'
+
+entry_points = {
+    'zest.releaser.prereleaser.before': [
+        # XXX: This only works doing fullrelease
+        'rm_cflags = icrs.releaser.removecflags:prereleaser_before',
+    ],
+    'zest.releaser.prereleaser.middle': [
+        'version_next = icrs.releaser.versionreplacer:prereleaser_middle',
+        # XXX: This only works doing fullrelease
+        'scm_middle = icrs.releaser.setuptools_scm_versionfixer:prereleaser_middle',
+        'dev_middle = icrs.releaser.devremover:prereleaser_middle',
+    ],
+    'console_scripts': [
+        'icrs_release = icrs.releaser.fullrelease:main',
+    ]
+}
+
+TESTS_REQUIRE = [
+    'coverage',
+    'zope.testrunner',
+]
+
+def _read(fname):
+    with codecs.open(fname, encoding='utf-8') as f:
+        return f.read()
+
+setup(
+    name='icrs.releaser',
+    version=version,
+    author='Jason Madden',
+    author_email='jason@seecoresoftware.com',
+    description="zest.releaser/setuptools_scm plugin.",
+    long_description=_read('README.rst') + '\n\n' + _read('CHANGES.rst'),
+    license='Apache',
+    keywords='zest.releaser release automation setuptools_scm git',
+    url='https://github.com/jamadden/icrs.releaser',
+    project_urls={
+        'Documentation': 'https://icrsreleaser.readthedocs.io/en/latest/',
+    },
+    classifiers=[
+        'Intended Audience :: Developers',
+        'Natural Language :: English',
+        'Operating System :: OS Independent',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy',
+        'Development Status :: 1 - Planning',
+    ],
+    zip_safe=False,
+    packages=find_namespace_packages(where='src'),
+    package_dir={'': 'src'},
+    namespace_packages=['icrs'],
+    install_requires=[
+        # Placeholder
+        'zest.releaser >= 9.1.1',
+    ],
+    entry_points=entry_points,
+    include_package_data=True,
+    extras_require={
+        'test': TESTS_REQUIRE,
+        'docs': [
+            'Sphinx',
+            'furo',
+            'sphinxcontrib-programoutput',
+        ] + TESTS_REQUIRE,
+        'recommended': [
+            'zest.releaser[recommended]',
+        ],
+    },
+    python_requires=">=3.8",
+)
diff --git a/src/icrs/releaser/tests/test_devremover.py b/src/icrs/releaser/tests/test_devremover.py
new file mode 100644
index 0000000..afd92c7
--- /dev/null
+++ b/src/icrs/releaser/tests/test_devremover.py
@@ -0,0 +1,129 @@
+# -*- coding: utf-8 -*-
+"""
+Tests for devremover.py
+
+"""
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from importlib.resources import files
+
+
+class TestRegex(unittest.TestCase):
+
+    def _callFUT(self, s):
+        from ..devremover import _SETUP_PY_DEV_REQUIREMENT_MATCHER
+        s = s.encode('utf-8') if isinstance(s, str) else s
+        return _SETUP_PY_DEV_REQUIREMENT_MATCHER.search(s)
+
+    def _matches(self, s):
+        self.assertTrue(self._callFUT(s))
+
+    def test_simple_matches(self):
+        m = self._matches
+        for example in (
+            # double quotes
+            '"icrs.releaser >= 1.0.dev0"',
+            # single quotes
+            "'icrs.releaser >= 1.0.dev0'",
+            # Complex requirement
+            '"icrs.releaser != 2.0,>=1.0.dev0"',
+            # From PEP 508
+            '\'requests [security,tests] >= 2.8.1.dev0, == 2.8.* ; python_version < "2.7"\'',
+        ):
+            with self.subTest(example):
+                m(example)
+
+                example = f"""
+                install_requires = [
+                    {example},
+                ]
+                """
+                m(example)
+
+    def _no_match(self, s):
+        self.assertFalse(self._callFUT(s))
+
+    def test_simple_non_matches(self):
+        m = self._no_match
+        for example in (
+            # double quotes
+            '"icrs.releaser >= 1.0"',
+            # single quotes
+            "'icrs.releaser >= 1.0'",
+            # Complex requirement
+            '"icrs.releaser != 2.0,>=1.0"',
+            # From PEP 508
+            '\'requests [security,tests] >= 2.8.1, == 2.8.* ; python_version < "2.7"\'',
+            # A 'dev' substring in various places
+            "'foo.dev'",
+            "foo.dev.bar >= 1.0"
+        ):
+            with self.subTest(example):
+                m(example)
+
+                example = f"""
+                install_requires = [
+                    {example},
+                ]
+                """
+                m(example)
+
+class TestPrereleaser(unittest.TestCase):
+
+    def setUp(self):
+        super().setUp()
+        self._reports = []
+
+    def _report(self, *args, **_kw):
+        self._reports.append(args)
+
+    def _callFUT(self, data_dir):
+        from ..devremover import prereleaser_before as fut
+        data = {
+            'reporoot': data_dir,
+            'icrs.releaser:report': self._report,
+        }
+        return fut(data)
+
+    def test_no_dev_dep(self):
+        with tempfile.TemporaryDirectory(prefix='icrs_releaser_') as td:
+            td = Path(td)
+            setup = td / 'setup.py'
+
+            example = files('icrs.releaser.tests') / 'example_setup.txt'
+            setup.write_bytes(example.read_bytes())
+            self._callFUT(td)
+            self.assertTrue(self._reports)
+
+    def test_found_dev_dep(self):
+        from ..devremover import DevelopmentDependency
+        with tempfile.TemporaryDirectory(prefix='icrs_releaser_') as td:
+            td = Path(td)
+            setup = td / 'setup.py'
+
+            example = files('icrs.releaser.tests') / 'example_setup.txt'
+            example = example.read_bytes()
+            placeholder = b'# Placeholder'
+            dev_dep = b"'icrs.releaser >= 1.0.dev0',"
+            assert placeholder in example
+            example = example.replace(placeholder, dev_dep)
+            assert dev_dep in example
+
+            setup.write_bytes(example)
+            with self.assertRaisesRegex(DevelopmentDependency,
+                                        '.*setup.py had development dependency: '
+                                        + dev_dep.decode('utf-8')[:-2]):
+                self._callFUT(td)
+
+    def test_no_setup_file(self):
+        with tempfile.TemporaryDirectory(prefix='icrs_releaser_') as td:
+            self._callFUT(td)
+
+        self.assertTrue(self._reports)
+        self.assertEqual(2, len(self._reports))
+        self.assertIn('does not exist', ' '.join(str(s) for s in self._reports[1]))
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/tox.ini b/tox.ini
index 3a4c955..7da78bb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py38,py39,py310,py311,py312,pypy310,coverage,docs
+envlist = py39,py310,py311,py312,pypy310,coverage,docs
 
 [testenv]
 extras = test
@@ -17,7 +17,7 @@ commands =
     coverage report -i
     coverage html -i
     coverage xml -i
-depends = py38,py39,py310,pypy38,docs
+depends = py39,py310,pypy310,docs
 parallel_show_output = true
 
 [testenv:docs]