diff --git a/CHANGES.md b/CHANGES.md
index e44d3e5..759817b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -5,9 +5,14 @@ chronological order. Releases follow [semantic versioning](https://semver.org/)
 releases are available on [PyPI](https://pypi.org/project/pytask-r) and
 [Anaconda.org](https://anaconda.org/conda-forge/pytask-r).
 
-## 0.2.0 - 2022-xx-xx
+## 0.3.0 - 2023-xx-xx
+
+- {pull}`33` deprecates INI configurations and aligns the plugin with pytask v0.3.
+
+## 0.2.0 - 2022-04-16
 
 - {pull}`24` removes an unnecessary hook implementation.
+- {pull}`26` implements the new interface for v0.2.
 
 ## 0.1.1 - 2022-02-08
 
diff --git a/README.md b/README.md
index 7d90f84..0ffeef9 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 [![image](https://img.shields.io/conda/vn/conda-forge/pytask-r.svg)](https://anaconda.org/conda-forge/pytask-r)
 [![image](https://img.shields.io/conda/pn/conda-forge/pytask-r.svg)](https://anaconda.org/conda-forge/pytask-r)
 [![PyPI - License](https://img.shields.io/pypi/l/pytask-r)](https://pypi.org/project/pytask-r)
-[![image](https://img.shields.io/github/workflow/status/pytask-dev/pytask-r/main/main)](https://github.com/pytask-dev/pytask-r/actions?query=branch%3Amain)
+[![image](https://img.shields.io/github/actions/workflow/status/pytask-dev/pytask-r/main.yml?branch=main)](https://github.com/pytask-dev/pytask-r/actions?query=branch%3Amain)
 [![image](https://codecov.io/gh/pytask-dev/pytask-r/branch/main/graph/badge.svg)](https://codecov.io/gh/pytask-dev/pytask-r)
 [![pre-commit.ci status](https://results.pre-commit.ci/badge/github/pytask-dev/pytask-r/main.svg)](https://results.pre-commit.ci/latest/github/pytask-dev/pytask-r/main)
 [![image](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
diff --git a/environment.yml b/environment.yml
index 836ac2c..e08ca6f 100644
--- a/environment.yml
+++ b/environment.yml
@@ -16,8 +16,8 @@ dependencies:
   - conda-verify
 
   # Package dependencies
-  - pytask >=0.2
-  - pytask-parallel >=0.2
+  - pytask >=0.3
+  - pytask-parallel >=0.3
 
   - r-base >4
   - r-jsonlite
diff --git a/setup.cfg b/setup.cfg
index 615dce3..35ed3b7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,7 +27,7 @@ packages = find:
 install_requires =
     click
     pybaum>=0.1.1
-    pytask>=0.2
+    pytask>=0.3
 python_requires = >=3.7
 include_package_data = True
 package_dir = =src
diff --git a/src/pytask_r/collect.py b/src/pytask_r/collect.py
index 84d668e..97dea84 100644
--- a/src/pytask_r/collect.py
+++ b/src/pytask_r/collect.py
@@ -14,7 +14,7 @@
 from pytask import produces
 from pytask import remove_marks
 from pytask import Task
-from pytask_r.serialization import SERIALIZER
+from pytask_r.serialization import SERIALIZERS
 from pytask_r.shared import r
 
 
@@ -101,9 +101,9 @@ def _parse_r_mark(mark, default_options, default_serializer, default_suffix):
 
     if (
         isinstance(parsed_kwargs["serializer"], str)
-        and parsed_kwargs["serializer"] in SERIALIZER
+        and parsed_kwargs["serializer"] in SERIALIZERS
     ):
-        proposed_suffix = SERIALIZER[parsed_kwargs["serializer"]]["suffix"]
+        proposed_suffix = SERIALIZERS[parsed_kwargs["serializer"]]["suffix"]
     else:
         proposed_suffix = default_suffix
     parsed_kwargs["suffix"] = suffix if suffix else proposed_suffix
diff --git a/src/pytask_r/config.py b/src/pytask_r/config.py
index faabb81..a135fbc 100644
--- a/src/pytask_r/config.py
+++ b/src/pytask_r/config.py
@@ -2,26 +2,28 @@
 from __future__ import annotations
 
 from pytask import hookimpl
+from pytask_r.serialization import SERIALIZERS
 
 
 @hookimpl
-def pytask_parse_config(config, config_from_file):
+def pytask_parse_config(config):
     """Register the r marker."""
     config["markers"]["r"] = "Tasks which are executed with Rscript."
-    config["r_serializer"] = config_from_file.get("r_serializer", "json")
-    config["r_suffix"] = config_from_file.get("r_suffix", "")
-    config["r_options"] = _parse_value_or_whitespace_option(
-        config_from_file.get("r_options")
-    )
+    config["r_serializer"] = config.get("r_serializer", "json")
+    if config["r_serializer"] not in SERIALIZERS:
+        raise ValueError(
+            f"'r_serializer' is {config['r_serializer']} and not one of "
+            f"{list(SERIALIZERS)}."
+        )
+    config["r_suffix"] = config.get("r_suffix", "")
+    config["r_options"] = _parse_value_or_whitespace_option(config.get("r_options"))
 
 
 def _parse_value_or_whitespace_option(value: str | None) -> None | str | list[str]:
     """Parse option which can hold a single value or values separated by new lines."""
-    if value in ["none", "None", None, ""]:
+    if value is None:
         return None
     elif isinstance(value, list):
         return list(map(str, value))
-    elif isinstance(value, str):
-        return [v.strip() for v in value.split(" ") if v.strip()]
     else:
-        raise ValueError(f"Input {value!r} is neither a 'str' nor 'None'.")
+        raise ValueError(f"'r_options' is {value} and not a list.")
diff --git a/src/pytask_r/serialization.py b/src/pytask_r/serialization.py
index 9bb0499..a68b57f 100644
--- a/src/pytask_r/serialization.py
+++ b/src/pytask_r/serialization.py
@@ -12,7 +12,7 @@
 _HIDDEN_FOLDER = ".pytask"
 
 
-SERIALIZER = {"json": {"serializer": json.dumps, "suffix": ".json"}}
+SERIALIZERS = {"json": {"serializer": json.dumps, "suffix": ".json"}}
 
 
 try:
@@ -20,8 +20,8 @@
 except ImportError:  # pragma: no cover
     pass
 else:
-    SERIALIZER["yaml"] = {"serializer": yaml.dump, "suffix": ".yaml"}
-    SERIALIZER["yml"] = {"serializer": yaml.dump, "suffix": ".yml"}
+    SERIALIZERS["yaml"] = {"serializer": yaml.dump, "suffix": ".yaml"}
+    SERIALIZERS["yml"] = {"serializer": yaml.dump, "suffix": ".yml"}
 
 
 def create_path_to_serialized(task: Task, suffix: str) -> Path:
@@ -56,8 +56,8 @@ def serialize_keyword_arguments(
 ) -> None:
     if callable(serializer):
         serializer_func = serializer
-    elif isinstance(serializer, str) and serializer in SERIALIZER:
-        serializer_func = SERIALIZER[serializer]["serializer"]
+    elif isinstance(serializer, str) and serializer in SERIALIZERS:
+        serializer_func = SERIALIZERS[serializer]["serializer"]
     else:
         raise ValueError(f"Serializer {serializer!r} is not known.")
 
diff --git a/src/pytask_r/shared.py b/src/pytask_r/shared.py
index 36026af..db9ccc8 100644
--- a/src/pytask_r/shared.py
+++ b/src/pytask_r/shared.py
@@ -6,42 +6,7 @@
 from typing import Sequence
 
 
-_ERROR_MSG = """The old syntax for @pytask.mark.r was suddenly deprecated starting \
-with pytask-r v0.2 to provide a better user experience. Thank you for your \
-understanding!
-
-It is recommended to upgrade to the new syntax, so you enjoy all the benefits of v0.2 \
-of pytask and pytask-r which is among others access to 'depends_on' and 'produces', \
-and other kwargs inside the R script.
-
-You can find a manual here: \
-https://github.com/pytask-dev/pytask-r/blob/v0.2.0/README.md
-
-Upgrading can be as easy as rewriting your current task from
-
-    @pytask.mark.r(["--option", "path_to_dependency.txt"])
-    @pytask.mark.depends_on("script.R")
-    @pytask.mark.produces("out.csv")
-    def task_r():
-        ...
-
-to
-
-    @pytask.mark.r(script="script.r", options="--option")
-    @pytask.mark.depends_on("path_to_dependency.txt")
-    @pytask.mark.produces("out.csv")
-    def task_r():
-        ...
-
-You can also fix the version of pytask and pytask-r to <0.2, so you do not have to \
-to upgrade. At the same time, you will not enjoy the improvements released with \
-version v0.2 of pytask and pytask-r.
-
-"""
-
-
 def r(
-    *args,
     script: str | Path = None,
     options: str | Iterable[str] | None = None,
     serializer: str | Callable[..., str] | str | None = None,
@@ -70,9 +35,6 @@ def r(
         ``".json"``.
 
     """
-    if args or script is None:
-        raise RuntimeError(_ERROR_MSG)
-
     options = [] if options is None else list(map(str, _to_list(options)))
     return script, options, serializer, suffix
 
diff --git a/tests/test_collect.py b/tests/test_collect.py
index fa78c14..b9cd250 100644
--- a/tests/test_collect.py
+++ b/tests/test_collect.py
@@ -6,26 +6,13 @@
 from pytask import Mark
 from pytask_r.collect import _parse_r_mark
 from pytask_r.collect import r
-from pytask_r.serialization import SERIALIZER
+from pytask_r.serialization import SERIALIZERS
 
 
 @pytest.mark.unit
 @pytest.mark.parametrize(
     "args, kwargs, expectation, expected",
     [
-        ((), {}, pytest.raises(RuntimeError, match="The old syntax"), None),
-        (
-            ("-o"),
-            {"script": "script.r"},
-            pytest.raises(RuntimeError, match="The old syntax"),
-            None,
-        ),
-        (
-            (),
-            {"options": ("-o")},
-            pytest.raises(RuntimeError, match="The old syntax"),
-            None,
-        ),
         (
             (),
             {
@@ -60,31 +47,6 @@ def test_r(args, kwargs, expectation, expected):
 @pytest.mark.parametrize(
     "mark, default_options, default_serializer, default_suffix, expectation, expected",
     [
-        (
-            Mark("r", (), {}),
-            [],
-            None,
-            ".json",
-            pytest.raises(RuntimeError, match="The old syntax for @pytask.mark.r"),
-            Mark(
-                "r",
-                (),
-                {
-                    "script": None,
-                    "options": [],
-                    "serializer": None,
-                    "suffix": ".json",
-                },
-            ),
-        ),
-        (
-            Mark("r", ("-o"), {}),
-            [],
-            None,
-            ".json",
-            pytest.raises(RuntimeError, match="The old syntax for @pytask.mark.r"),
-            None,
-        ),
         (
             Mark("r", (), {"script": "script.r"}),
             [],
@@ -122,7 +84,7 @@ def test_r(args, kwargs, expectation, expected):
                     "script": "script.r",
                     "options": [],
                     "serializer": "json",
-                    "suffix": SERIALIZER["json"]["suffix"],
+                    "suffix": SERIALIZERS["json"]["suffix"],
                 },
             ),
         ),
diff --git a/tox.ini b/tox.ini
index 706acb7..a3c2fa8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,8 +9,8 @@ basepython = python
 
 [testenv:pytest]
 conda_deps =
-    pytask >=0.1.0
-    pytask-parallel >=0.1.0
+    pytask >=0.3
+    pytask-parallel >=0.3
     pybaum >=0.1.1
 
     # Optional dependencies.