diff --git a/doc/requirements.txt b/doc/requirements.txt
index fabcc7e1..7ef7b3d1 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,7 +1,3 @@
-# The order of packages is significant, because pip processes them in the order
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
-# Notes:
 # reno needs openstackdocstheme which needs reno (cycle dep).
 # os-api-ref needs openstackdocstheme which needs os-api-ref (cycle dep).
 # Put them in here will make it clear that those are only needed for
diff --git a/requirements.txt b/requirements.txt
index f2932eac..6063175b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,3 @@
-# The order of packages is significant, because pip processes them in the order
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
-
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 dulwich>=0.15.0 # Apache-2.0
+sphinx>=2.0.0,!=2.1.0 # BSD
diff --git a/test-requirements.txt b/test-requirements.txt
deleted file mode 100644
index dbb099e3..00000000
--- a/test-requirements.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-# The order of packages is significant, because pip processes them in the order
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
-
-hacking>=3.0.1,<3.1.0 # Apache-2.0
-
-# this is required for the docs build jobs
-sphinx>=2.0.0,!=2.1.0 # BSD
-
-pre-commit>=2.6.0 # MIT
diff --git a/tox.ini b/tox.ini
index 2d5fd834..c15e6c38 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,25 +1,26 @@
 [tox]
-minversion = 3.1.0
+minversion = 4.6.0
 envlist = pep8
-ignore_basepython_conflict = true
 
 [testenv]
-basepython = python3
 usedevelop = true
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/upper-constraints.txt}
-    -r{toxinidir}/test-requirements.txt
-    -r{toxinidir}/requirements.txt
-    -r{toxinidir}/doc/requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/upper-constraints.txt}
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/doc/requirements.txt
 sitepackages = False
 allowlist_externals =
   rm
   make
 
 [testenv:pep8]
+description =
+  Run style checks.
+skip_install = true
+deps =
+  pre-commit
 commands =
-    pre-commit run -a
-    flake8 openstackdocstheme
+  pre-commit run -a
 
 [testenv:venv]
 commands = {posargs}