diff --git a/.stestr.conf b/.stestr.conf
new file mode 100644
index 000000000..5ed95bafd
--- /dev/null
+++ b/.stestr.conf
@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=${TEST_PATH:-./tripleo_validations/tests}
+top_dir=./
diff --git a/test-requirements.txt b/test-requirements.txt
index 81ee12b90..5785d774f 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -14,3 +14,4 @@ testtools>=2.2.0 # MIT
 reno>=3.1.0 # Apache-2.0
 netaddr>=0.7.18 # BSD
 pre-commit # MIT
+stestr>=3.0.1 # Apache-2.0
diff --git a/tools/validate-files.py b/tools/validate-files.py
index 7b35e06a6..afdce674f 100755
--- a/tools/validate-files.py
+++ b/tools/validate-files.py
@@ -22,7 +22,7 @@ def exit_usage():
 
 
 def validate_library_file(file_path):
-    with open(file_path) as f:
+    with open(file_path, encoding='utf-8') as f:
         file_content = f.read()
         if 'DOCUMENTATION = ' not in file_content \
                 or 'EXAMPLES = ' not in file_content:
diff --git a/tox.ini b/tox.ini
index 73ec4bb2b..abc5f5aec 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ ignore_basepython_conflict = True
 [testenv]
 basepython = python3
 usedevelop = True
-passenv = *
+passenv = TERM
 setenv =
   ANSIBLE_CALLBACK_PLUGINS={toxinidir}/callback_plugins
   ANSIBLE_LOOKUP_PLUGINS={toxinidir}/lookup_plugins
@@ -21,8 +21,13 @@ setenv =
   # paramiko CryptographyDeprecationWarning: https://github.com/ansible/ansible/issues/52598
   PYTHONWARNINGS=ignore:DEPRECATION::pip._internal.cli.base_command,ignore::UserWarning
   PIP_DISABLE_PIP_VERSION_CHECK=1
-commands = python setup.py test --slowest --testr-args='{posargs}'
-sitepackages = True
+  PIP_+  VIRTUAL_ENV={envdir}
+  LANG=en_US.UTF-8
+  LANGUAGE=en_US:en
+  LC_ALL=C
+  HOME={envdir}
+commands =
+    stestr run --slowest --color {posargs}
 deps =
     -c {env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
     -r {toxinidir}/requirements.txt