diff --git a/.coveragerc b/.coveragerc
index 4582306..6a34e66 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,5 +1,7 @@
 [run]
-omit = .tox/*
+omit =
+	# leading `*/` for pytest-dev/pytest-cov#456
+	*/.tox/*
 
 [report]
 show_missing = True
diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..6385b57
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,15 @@
+root = true
+
+[*]
+charset = utf-8
+indent_style = tab
+indent_size = 4
+insert_final_newline = true
+end_of_line = lf
+
+[*.py]
+indent_style = space
+
+[*.{yml,yaml}]
+indent_style = space
+indent_size = 2
diff --git a/pytest.ini b/pytest.ini
index 63f4a2b..3660d3d 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -6,5 +6,3 @@ doctest_optionflags=ALLOW_UNICODE ELLIPSIS
 # workaround for warning pytest-dev/pytest#6178
 junit_family=xunit2
 filterwarnings=
-    # https://github.com/pytest-dev/pytest/issues/6928
-    ignore:direct construction of .*Item has been deprecated:DeprecationWarning
diff --git a/setup.cfg b/setup.cfg
index c3fbea9..c69f6b4 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -32,13 +32,17 @@ exclude =
 [options.extras_require]
 testing =
 	# upstream
-	pytest >= 3.5, !=3.7.3
-	pytest-checkdocs >= 1.2.3
+	pytest >= 4.6
+	pytest-checkdocs >= 2.4
 	pytest-flake8
-	pytest-black >= 0.3.7; python_implementation != "PyPy"
+	# python_implementation: workaround for jaraco/skeleton#22
+	# python_version: workaround for python/typed_ast#156
+	pytest-black >= 0.3.7; python_implementation != "PyPy" and python_version < "3.10"
 	pytest-cov
-	pytest-mypy; python_implementation != "PyPy"
-	pytest-enabler
+	# python_implementation: workaround for jaraco/skeleton#22
+	# python_version: workaround for python/typed_ast#156
+	pytest-mypy; python_implementation != "PyPy" and python_version < "3.10"
+	pytest-enabler >= 1.0.1
 
 	# local
 	jaraco.classes
diff --git a/tox.ini b/tox.ini
index 542537b..26f897e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,7 +27,7 @@ commands =
 skip_install = True
 deps =
 	build
-	twine[keyring]>=1.13
+	twine>=3
 	path
 	jaraco.develop>=7.1
 passenv =