diff --git a/README.md b/README.md
index ad53fe8..6eebc14 100644
--- a/README.md
+++ b/README.md
@@ -41,9 +41,9 @@ release history.
 - Manage package versions in exactly one place and with exactly one tool: Poetry.
 - Ensure CI/CD and other automation tools are using the same package versions that you are
   in your local development environment.
-- Add only the packages you need to a Tox test environment, instead of everything in your
-  lockfile.
-- Directly integrate with Poetry, re-using your existing package indexes and credentials
+- Add only the packages or custom groups you need to a Tox test environment, instead of
+  everything in your lockfile.
+- Directly integrate with Poetry, re-using your existing package indexes and credentials,
   with no additional configuration.
 - Wherever possible, built-in Tox config options are always respected and their behavior
   kept consistent.
@@ -198,11 +198,14 @@ configuration section.
 | :--------------------- | :-----: | :-----: | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `locked_deps`          |  List   |  `[]`   | Names of packages to install to the test environment from the Poetry lockfile. Transient dependencies (packages required by these dependencies) are automatically included.                                                                                                                                                                                          |
 | `require_locked_deps`  | Boolean |  False  | Whether the plugin should block attempts to install unlocked dependencies to the test environment. If enabled, then the [`tox_testenv_install_deps`](https://tox.readthedocs.io/en/latest/plugins.html#tox.hookspecs.tox_testenv_install_deps) plugin hook will be intercepted and an error will be raised if the test environment has the `deps` option configured. |
-| `install_dev_deps`     | Boolean |  False  | Whether all of the Poetry dev-dependencies should be installed to the test environment.                                                                                                                                                                                                                                                                              |
 | `install_project_deps` | Boolean |  True   | Whether all of the Poetry primary dependencies for the project package should be installed to the test environment.                                                                                                                                                                                                                                                  |
 | `require_poetry`       | Boolean |  False  | Whether Tox should be forced to fail if the plugin cannot import Poetry locally. If `False` then the plugin will be skipped for the test environment if Poetry cannot be imported. If `True` then the plugin will force the environment to error and the Tox run to fail.                                                                                            |
 | `poetry_dep_groups`    |  List   |  `[]`   | Names of Poetry dependency groups specified in `pyproject.toml` to install to the test environment.                                                                                                                                                                                                                                                                  |
 
+> **Note:** The `install_dev_deps` configuration option is deprecated and will be removed in
+> version 1.0.0. Please set `poetry_dep_groups = [dev]` in `tox.ini` for environments that
+> install the development dependencies.
+
 ### Runtime Options
 
 All arguments listed below can be passed to the `tox` command to modify runtime behavior
diff --git a/tox_poetry_installer/hooks.py b/tox_poetry_installer/hooks.py
index de27e29..ef1ed31 100644
--- a/tox_poetry_installer/hooks.py
+++ b/tox_poetry_installer/hooks.py
@@ -115,7 +115,7 @@ def tox_addoption(parser: ToxParser):
         name="install_dev_deps",
         type="bool",
         default=False,
-        help="Automatically install all Poetry development dependencies to the environment",
+        help="(deprecated) Automatically install all Poetry development dependencies to the environment",
     )
 
     parser.add_testenv_attribute(
diff --git a/tox_poetry_installer/utilities.py b/tox_poetry_installer/utilities.py
index 5aeba8e..000cd14 100644
--- a/tox_poetry_installer/utilities.py
+++ b/tox_poetry_installer/utilities.py
@@ -59,6 +59,13 @@ def check_preconditions(venv: ToxVirtualEnv, action: ToxAction) -> "_poetry.Poet
             "be removed in version 1.0.0. Please use the '--parallel-install-threads' option."
         )
 
+    if venv.envconfig.install_dev_deps:
+        logger.warning(
+            "DEPRECATION: The 'install_dev_deps' option is deprecated and will be removed in "
+            "version 1.0.0. Please update test environments that install development dependencies "
+            "to set the 'poetry_dev_groups = [dev]' option in tox.ini"
+        )
+
     from tox_poetry_installer import _poetry
 
     try: