diff --git a/.github/workflows/tox.yaml b/.github/workflows/tox.yaml
index 2e50218e..8182e6b4 100644
--- a/.github/workflows/tox.yaml
+++ b/.github/workflows/tox.yaml
@@ -9,7 +9,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.8', '3.10', '3.11', '3.12']
+        python-version:
+          - '3.8'  # focal
+          - '3.10' # jammy
+          - '3.12' # noble
     steps:
     - uses: actions/checkout@v1
     - name: Set up Python ${{ matrix.python-version }}
diff --git a/setup.py b/setup.py
index 91739dda..b93f897c 100644
--- a/setup.py
+++ b/setup.py
@@ -25,16 +25,13 @@
 
 version = "0.0.1.dev1"
 install_require = [
+    'importlib-metadata<8.0.0',  # compatible with py38
+    'setuptools_scm<8.2.0',  # https://github.com/canonical/charmcraft/pull/2275
     'aiohttp<4.0.0',  # aiohttp/_http_parser.c:16227:5: error: lvalue required as increment operand
     'oslo.config<6.12.0',  # pin at stable/train to retain Py3.5 support
     'async_generator',
-
-    # Newer versions require a Rust compiler to build, see
-    # * https://github.com/openstack-charmers/zaza/issues/421
-    # * https://mail.python.org/pipermail/cryptography-dev/2021-January/001003.html
-    'cryptography<3.4',
-
-    'hvac<0.7.0',
+    'cryptography',
+    'hvac',
     'jinja2',
     'juju-wait',
     'PyYAML',
diff --git a/test-requirements.txt b/test-requirements.txt
index 5557c6f9..cce41cee 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,8 +1,8 @@
 aiounittest
+pydocstyle<4.0.0
 flake8>=5  # Python 3.8 compatibility in pyflakes 2.1.0+
 flake8-docstrings
 flake8-per-file-ignores
-pydocstyle<4.0.0
 coverage
 mock>=1.2
 pytest
diff --git a/tox.ini b/tox.ini
index f6423005..0c62fa97 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,6 +21,7 @@ passenv =
 deps =
     -c{env:PIP_CONSTRAINTS:{toxinidir}/constraints-juju29.txt}
     -r{toxinidir}/test-requirements.txt
+install_command = python -I -m pip install --no-binary ":all:" {opts} {packages}
 commands = pytest --cov=./zaza/ {posargs} {toxinidir}/unit_tests
 
 [testenv:.pkg]