diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4b31f805b..f6581a386 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -119,7 +119,7 @@ jobs:
         with:
           python-version: "3.14"
           activate-environment: 'true'
-      - run: uv pip install -e .[dev] pytest-codspeed
+      - run: uv pip install -e . --group dev pytest-codspeed
       - run: make import-cldr
       - uses: CodSpeedHQ/action@88472375d0a4572cf70a9f1fe3a4e0ab8da1b924 # v5.0.1
         with:
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9f39be1cc..65e65c82b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -13,7 +13,7 @@ After you've cloned the repository,
 
 1. Set up a Python virtualenv (the methods vary depending on tooling and operating system)
   and activate it.
-2. Install Babel in editable mode with development dependencies: `pip install -e .[dev]`
+2. Install Babel in editable mode with development dependencies: `pip install -e . --group dev`
 3. Run `make import-cldr` to import the CLDR database.
   This will download the CLDR database and convert it to a format that Babel can use.
 4. Run `make test` to run the tests. You can also run e.g. `pytest --cov babel .` to
diff --git a/pyproject.toml b/pyproject.toml
index d873f86c0..8b85ee256 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,22 +37,26 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 
-[project.optional-dependencies]
-# TODO: use a `dev` dependency group instead
-dev = [
+[project.urls]
+Homepage = "https://babel.pocoo.org/"
+Source = "https://github.com/python-babel/babel"
+
+[dependency-groups]
+# Bare minimum to run the test suite
+test = [
     "freezegun~=1.0",
-    "jinja2>=3.0",
     "pytest-cov",
     "pytest>=6.0",
+    "tzdata;sys_platform == 'win32'",
+]
+# Optional packages Babel integrates with
+dev = [
+    { include-group = "test" },
+    "jinja2>=3.0",
     "pytz",
     "setuptools",
-    "tzdata;sys_platform == 'win32'",
 ]
 
-[project.urls]
-Homepage = "https://babel.pocoo.org/"
-Source = "https://github.com/python-babel/babel"
-
 [tool.hatch.version]
 path = "babel/__init__.py"
 
diff --git a/tox.ini b/tox.ini
index ece8b148d..43a00abfd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,17 +1,17 @@
 [tox]
 isolated_build = true
 envlist =
-    py{38,39,310,311,312,313,314,315}
+    py{39,310,311,312,313,314,315}
     pypy3
-    py{38}-pytz
-    py{311,312,313,314,315}-setuptools
-    py{312,313,314,315}-jinja
+    py314-bare
 
 [testenv]
 # The CLDR data is imported by `commands`, so isn't there yet when packaging
 package = editable
-extras =
-    dev
+dependency_groups =
+    !bare: dev
+    # The bare environment runs the tests without optional dependencies (pytz, jinja2, setuptools)
+    bare: test
 deps =
     # On Python 3.9, we need a version of Setuptools that still has pkg_resources
     # to be able to run the Jinja extractor tests.