diff --git a/test-requirements.txt b/test-requirements.txt
index 196337f75..152b46dc4 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -18,3 +18,4 @@ testresources>=2.0.0 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 stestr>=1.0.0 # Apache-2.0
+Pygments>=2.2.0 # BSD license
diff --git a/tox.ini b/tox.ini
index 7fd0cf45f..2ff1f7d8e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -25,7 +25,7 @@ passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:pep8]
 commands =
-  doc8 -e .rst doc/source/ CONTRIBUTING.rst HACKING.rst README.rst --ignore D000
+  doc8 -e .rst doc/source/ CONTRIBUTING.rst HACKING.rst README.rst
   bash tools/flake8wrap.sh {posargs}
   # The following bandit tests are being skipped:
   # B303 - Use of insecure MD2, MD4, or MD5 hash function.