diff --git a/pyproject.toml b/pyproject.toml
index 845e4b7..2e881f4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,17 +41,37 @@ dynamic = [
 dependencies = [
   "sphinx>=9.0.4",
 ]
-optional-dependencies.testing = [
-  "covdefaults>=2.3",
-  "defusedxml>=0.7.1", # needed for sphinx.testing
-  "pytest>=9.0.2",
-  "pytest-cov>=7",
-]
 urls.Documentation = "https://github.com/tox-dev/sphinx-argparse-cli#sphinx-argparse-cli"
 urls.Homepage = "https://github.com/tox-dev/sphinx-argparse-cli"
 urls.Source = "https://github.com/tox-dev/sphinx-argparse-cli"
 urls.Tracker = "https://github.com/tox-dev/sphinx-argparse-cli/issues"
 
+[dependency-groups]
+dev = [
+  { include-group = "lint" },
+  { include-group = "pkg-meta" },
+  { include-group = "test" },
+  { include-group = "type" },
+]
+test = [
+  "covdefaults>=2.3",
+  "defusedxml>=0.7.1",
+  "pytest>=9.0.2",
+  "pytest-cov>=7",
+]
+type = [
+  "ty>=0.0.17",
+  { include-group = "test" },
+]
+lint = [
+  "pre-commit-uv>=4.2",
+]
+pkg-meta = [
+  "check-wheel-contents>=0.6.3",
+  "twine>=6.2",
+  "uv>=0.9.16",
+]
+
 [tool.hatch]
 build.hooks.vcs.version-file = "src/sphinx_argparse_cli/version.py"
 build.targets.sdist.include = [
diff --git a/tox.toml b/tox.toml
index 6224c50..05c1f70 100644
--- a/tox.toml
+++ b/tox.toml
@@ -6,7 +6,7 @@ skip_missing_interpreters = true
 description = "run the unit tests with pytest under {env_name}"
 package = "wheel"
 wheel_build_env = ".pkg"
-extras = [ "testing" ]
+dependency_groups = [ "test" ]
 pass_env = [ "PYTEST_*" ]
 set_env.COVERAGE_FILE = { replace = "env", name = "COVERAGE_FILE", default = "{work_dir}{/}.coverage.{env_name}" }
 commands = [
@@ -38,13 +38,13 @@ commands = [
 [env.fix]
 description = "format the code base to adhere to our styles, and complain about what we cannot do automatically"
 skip_install = true
-deps = [ "pre-commit-uv>=4.2" ]
+dependency_groups = [ "lint" ]
 commands = [ [ "pre-commit", "run", "--all-files", "--show-diff-on-failure" ] ]
 
 [env.pkg_meta]
 description = "check that the long description is valid"
 skip_install = true
-deps = [ "check-wheel-contents>=0.6.3", "twine>=6.2", "uv>=0.9.16" ]
+dependency_groups = [ "pkg-meta" ]
 commands = [
   [ "uv", "build", "--sdist", "--wheel", "--out-dir", "{env_tmp_dir}", "." ],
   [ "twine", "check", "{env_tmp_dir}{/}*" ],
@@ -53,12 +53,13 @@ commands = [
 
 [env.type]
 description = "run type check on code base"
-deps = [ "ty>=0.0.17" ]
+dependency_groups = [ "type" ]
 commands = [ [ "ty", "check", "--output-format", "concise", "--error-on-warning", "." ] ]
 
 [env.dev]
 description = "generate a DEV environment"
 package = "editable"
+dependency_groups = [ "dev" ]
 commands = [
   [ "uv", "pip", "tree" ],
   [ "python", "-c", "import sys; print(sys.executable)" ],