diff --git a/pyproject.toml b/pyproject.toml
index d74fe7bf96..d5313c64cf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -99,3 +99,29 @@ line-length = 120
 
 [tool.ruff.isort]
 combine-as-imports = true
+
+[tool.mypy]
+ignore_missing_imports = true
+strict = true
+
+[[tool.mypy.overrides]]
+module = "tests.*"
+disallow_untyped_defs = false
+check_untyped_defs = true
+
+[tool.pytest.ini_options]
+addopts = "-rxXs"
+filterwarnings = [
+  "error",
+  "ignore: You seem to already have a custom sys.excepthook handler installed. I'll skip installing Trio's custom handler, but this means MultiErrors will not show full tracebacks.:RuntimeWarning",
+  # See: https://github.com/agronholm/anyio/issues/508
+  "ignore: trio.MultiError is deprecated since Trio 0.22.0:trio.TrioDeprecationWarning"
+]
+markers = [
+  "copied_from(source, changes=None): mark test as copied from somewhere else, along with a description of changes made to accodomate e.g. our test setup",
+  "network: marks tests which require network connection. Used in 3rd-party build environments that have network disabled."
+]
+
+[tool.coverage.run]
+omit = ["venv/*", "httpx/_compat.py"]
+include = ["httpx/*", "tests/*"]
diff --git a/requirements.txt b/requirements.txt
index b2ac31891f..840ecd0cf2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ twine==4.0.2
 
 # Tests & Linting
 black==23.3.0
-coverage==7.2.2
+coverage[toml]==7.2.2
 cryptography==40.0.2
 mypy==1.0.1
 types-certifi==2021.10.8.2
diff --git a/setup.cfg b/setup.cfg
deleted file mode 100644
index 728160bf86..0000000000
--- a/setup.cfg
+++ /dev/null
@@ -1,22 +0,0 @@
-[mypy]
-ignore_missing_imports = True
-strict = True
-
-[mypy-tests.*]
-disallow_untyped_defs = False
-check_untyped_defs = True
-
-[tool:pytest]
-addopts = -rxXs
-filterwarnings =
-  error
-  ignore: You seem to already have a custom sys.excepthook handler installed. I'll skip installing Trio's custom handler, but this means MultiErrors will not show full tracebacks.:RuntimeWarning
-  # See: https://github.com/agronholm/anyio/issues/508
-  ignore: trio\.MultiError is deprecated since Trio 0\.22\.0:trio.TrioDeprecationWarning
-markers =
-  copied_from(source, changes=None): mark test as copied from somewhere else, along with a description of changes made to accodomate e.g. our test setup
-  network: marks tests which require network connection. Used in 3rd-party build environments that have network disabled.
-
-[coverage:run]
-omit = venv/*, httpx/_compat.py
-include = httpx/*, tests/*