diff --git a/etc/scripts/fix_thirdparty.py b/etc/scripts/fix_thirdparty.py
index 9d401cd1..d664c9c4 100644
--- a/etc/scripts/fix_thirdparty.py
+++ b/etc/scripts/fix_thirdparty.py
@@ -78,7 +78,7 @@ def fix_thirdparty_dir(
         package_envts_not_fetched = utils_thirdparty.fetch_missing_wheels(dest_dir=thirdparty_dir)
         print("***FETCH*** MISSING SOURCES")
         src_name_ver_not_fetched = utils_thirdparty.fetch_missing_sources(dest_dir=thirdparty_dir)
-    
+
         package_envts_not_built = []
         if build_wheels:
             print("***BUILD*** MISSING WHEELS")
@@ -89,7 +89,7 @@ def fix_thirdparty_dir(
                 dest_dir=thirdparty_dir,
             )
             package_envts_not_built, _wheel_filenames_built = results
-    
+
         print("***ADD*** ABOUT AND LICENSES")
         utils_thirdparty.add_fetch_or_update_about_and_license_files(
             dest_dir=thirdparty_dir,
@@ -99,7 +99,7 @@ def fix_thirdparty_dir(
         # report issues
         for name, version in src_name_ver_not_fetched:
             print(f"{name}=={version}: Failed to fetch source distribution.")
-    
+
         for package, envt in package_envts_not_built:
             print(
                 f"{package.name}=={package.version}: Failed to build wheel "
diff --git a/etc/scripts/utils_requirements.py b/etc/scripts/utils_requirements.py
index fc331f65..7753ea02 100644
--- a/etc/scripts/utils_requirements.py
+++ b/etc/scripts/utils_requirements.py
@@ -86,7 +86,7 @@ def has_ops(l):
         return any(op in l for op in ops)
 
     if not has_ops:
-        return  line
+        return line
 
     splitter = re.compile(r"[><!=~;, \[\]]+").split
     return splitter(line)[0]
diff --git a/etc/scripts/utils_thirdparty.py b/etc/scripts/utils_thirdparty.py
index 676e22bb..a2fbe4e5 100644
--- a/etc/scripts/utils_thirdparty.py
+++ b/etc/scripts/utils_thirdparty.py
@@ -97,12 +97,14 @@
     "310": "3.10",
 }
 
+
 def get_python_dot_version(version):
     """
     Return a dot version from a plain, non-dot version.
     """
     return PYTHON_DOT_VERSIONS_BY_VER[version]
 
+
 ABIS_BY_PYTHON_VERSION = {
     "36": ["cp36", "cp36m"],
     "37": ["cp37", "cp37m"],
@@ -2529,7 +2531,7 @@ def hash_requirements(dest_dir=THIRDPARTY_DIR, requirements_file="requirements.t
 
 
 def add_fetch_or_update_about_and_license_files(
-    dest_dir=THIRDPARTY_DIR, 
+    dest_dir=THIRDPARTY_DIR,
     include_remote=True,
     strip_classifiers=False,
 ):
diff --git a/setup.cfg b/setup.cfg
index 5427f0ea..81f762a5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -39,6 +39,7 @@ where=src
 testing =
     pytest >= 6, != 7.0.0
     pytest-xdist >= 2
+    black
 docs=
     Sphinx>=3.3.1
     sphinx-rtd-theme>=0.5.0
diff --git a/tests/test_skeleton_codestyle.py b/tests/test_skeleton_codestyle.py
new file mode 100644
index 00000000..2eb6e558
--- /dev/null
+++ b/tests/test_skeleton_codestyle.py
@@ -0,0 +1,36 @@
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# ScanCode is a trademark of nexB Inc.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/skeleton for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
+
+import subprocess
+import unittest
+import configparser
+
+
+class BaseTests(unittest.TestCase):
+    def test_skeleton_codestyle(self):
+        """
+        This test shouldn't run in proliferated repositories.
+        """
+        setup_cfg = configparser.ConfigParser()
+        setup_cfg.read("setup.cfg")
+        if setup_cfg["metadata"]["name"] != "skeleton":
+            return
+
+        args = "venv/bin/black --check -l 100 setup.py etc tests"
+        try:
+            subprocess.check_output(args.split())
+        except subprocess.CalledProcessError as e:
+            print("===========================================================")
+            print(e.output)
+            print("===========================================================")
+            raise Exception(
+                "Black style check failed; please format the code using:\n"
+                "  python -m black -l 100 setup.py etc tests",
+                e.output,
+            ) from e