diff --git a/tests/test_slide_out.py b/tests/test_slide_out.py
index 663a69276..6fedc8183 100644
--- a/tests/test_slide_out.py
+++ b/tests/test_slide_out.py
@@ -7,7 +7,7 @@
                       mock_run_cmd_and_forward_stdout)
 
 
-class TestSlideout:
+class TestSlideOut:
 
     def setup_method(self, mocker: Any) -> None:
 
diff --git a/tests/test_status.py b/tests/test_status.py
index df39f81a8..a47add111 100644
--- a/tests/test_status.py
+++ b/tests/test_status.py
@@ -44,4 +44,5 @@ def test_branch_reappears_in_definition(self, mocker: Any) -> None:
         with pytest.raises(MacheteException) as e:
             launch_command('status')
         if e:
-            assert e.value.parameter == expected_error_message, 'Verify that expected error message has appeared a branch re-appears in tree definition.'
+            assert e.value.parameter == expected_error_message, \
+                'Verify that expected error message has appeared if a branch re-appears in tree definition.'
diff --git a/tox.ini b/tox.ini
index ff1bde81e..81941b7a1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,12 +12,12 @@ install_command =
   pip install {opts} {packages}
 deps =
   pytest
-  pytest-xdist
   pytest-mock
+  pytest-xdist
 allowlist_externals = mkdir
 commands =
   mkdir -p test-results/
-  pytest -n auto --junitxml=test-results/testenv-{envname}.xml {posargs}
+  pytest --numprocesses=auto --junitxml=test-results/testenv-{envname}.xml {posargs}
 
 [testenv:pep8]
 deps = flake8
@@ -38,8 +38,9 @@ commands = {posargs}
 [testenv:coverage]
 description = "Check the test coverage of the code"
 deps =
-  {[testenv]deps}
   coverage
+  pytest
+  pytest-mock
 commands =
   coverage erase
   # Generates .coverage binary file, used as the source of truth for the subsequent reports
@@ -69,4 +70,4 @@ deps =
   mypy
   pytest
 commands =
-  mypy --config-file mypy.ini git_machete tests
\ No newline at end of file
+  mypy --config-file mypy.ini git_machete tests