diff --git a/requirements.txt b/requirements.txt
index 46b4e99..b786b42 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,10 +11,6 @@ setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb
 # Build requirements
 charm-tools==2.8.3
 
-# Workaround until https://github.com/juju/charm-tools/pull/589 gets
-# published
-keyring<21
-
 simplejson
 
 # Newer versions use keywords that didn't exist in python 3.5 yet (e.g.
diff --git a/src/test-requirements.txt b/src/test-requirements.txt
index 520681e..e771023 100644
--- a/src/test-requirements.txt
+++ b/src/test-requirements.txt
@@ -3,12 +3,6 @@
 # choices of *requirements.txt files for OpenStack Charms:
 #     https://github.com/openstack-charmers/release-tools
 #
-# pep8 requirements
-charm-tools>=2.4.4
-
-# Workaround until https://github.com/juju/charm-tools/pull/589 gets
-# published
-keyring<21
 
 # Functional Test Requirements (let Zaza's dependencies solve all dependencies here!)
 git+https://github.com/openstack-charmers/zaza.git#egg=zaza
diff --git a/test-requirements.txt b/test-requirements.txt
index 0c0ad09..af069e1 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -4,8 +4,6 @@
 #     https://github.com/openstack-charmers/release-tools
 #
 setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb244e9b27bc56750c44b7c85
-# Lint and unit test requirements
-flake8>=2.2.4
 
 stestr>=2.2.0
 
@@ -47,7 +45,7 @@ git+https://github.com/openstack/charms.openstack.git#egg=charms.openstack
 netifaces        # vault
 psycopg2-binary  # vault
 tenacity         # vault
-pbr              # vault
+pbr==5.6.0       # vault
 cryptography<3.4 # vault, keystone-saml-mellon
 lxml             # keystone-saml-mellon
 hvac             # vault, barbican-vault
diff --git a/tox.ini b/tox.ini
index 391b2af..5c81801 100644
--- a/tox.ini
+++ b/tox.ini
@@ -62,7 +62,8 @@ commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
 basepython = python3
-deps = -r{toxinidir}/test-requirements.txt
+deps = flake8==3.9.2
+       charm-tools==2.8.3
 commands = flake8 {posargs} src unit_tests
 
 [testenv:cover]