diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index bc3ca89..518c003 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -61,21 +61,15 @@ erroneously.
 The tests are executed automatically for each PR using the ci (see
 `.github/workflow/lint.yml` and `.github/workflow/tests.yml`).
 
-Running the tests manually:
+Running the tests,
 
-* Using patroni's nominal replica state of `streaming` (since v3.0.4):
+* manually:
 
   ```bash
-  pytest ./tests
+  pytest tests
   ```
 
-* Using patroni's nominal replica state of `running` (before v3.0.4):
-
-  ```bash
-  pytest --use-old-replica-state ./tests
-  ```
-
-* Using tox:
+* or using tox:
 
   ```bash
   tox -e lint    # mypy + flake8 + black + isort ° codespell
@@ -83,9 +77,9 @@ Running the tests manually:
   tox -e py      # pytests and "lint" tests for the default version of python
   ```
 
-Please note that when dealing with any service that checks the state of a node
-in patroni's `cluster` endpoint, the corresponding JSON test file must be added
-in `./tests/tools.py`.
+Please note that when dealing with any service that checks the state of a node,
+the related tests must use the `old_replica_state` fixture to test with both
+old (pre 3.0.4) and new replica states.
 
 A bash script, `check_patroni.sh`, is provided to facilitate testing all
 services on a Patroni endpoint (`./vagrant/check_patroni.sh`). It requires one
diff --git a/tests/conftest.py b/tests/conftest.py
index 1bc7881..a5d0c4d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -8,25 +8,17 @@ from pytest_mock import MockerFixture
 from .tools import my_mock
 
 
-def pytest_addoption(parser: Any) -> None:
-    """
-    Add CLI options to `pytest` to pass those options to the test cases.
-    These options are used in `pytest_generate_tests`.
-    """
-    parser.addoption("--use-old-replica-state", action="store_true", default=False)
-
-
-def pytest_generate_tests(metafunc: Any) -> None:
-    metafunc.parametrize(
-        "use_old_replica_state", [metafunc.config.getoption("use_old_replica_state")]
-    )
+@pytest.fixture(
+    params=[False, True],
+    ids=lambda v: "new-replica-state" if v else "old-replica-state",
+)
+def old_replica_state(request: Any) -> Any:
+    return request.param
 
 
 @pytest.fixture
-def fake_restapi(
-    mocker: MockerFixture, use_old_replica_state: bool
-) -> Callable[..., Any]:
-    return partial(my_mock, mocker, use_old_replica_state=use_old_replica_state)
+def fake_restapi(mocker: MockerFixture) -> Callable[..., Any]:
+    return partial(my_mock, mocker)
 
 
 @pytest.fixture
diff --git a/tests/test_cluster_has_replica.py b/tests/test_cluster_has_replica.py
index df0e549..79539f5 100644
--- a/tests/test_cluster_has_replica.py
+++ b/tests/test_cluster_has_replica.py
@@ -4,8 +4,10 @@ from check_patroni.cli import main
 
 
 # TODO Lag threshold tests
-def test_cluster_has_relica_ok(runner: CliRunner, fake_restapi) -> None:
-    fake_restapi("cluster_has_replica_ok")
+def test_cluster_has_relica_ok(
+    runner: CliRunner, fake_restapi, old_replica_state: bool
+) -> None:
+    fake_restapi("cluster_has_replica_ok", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main, ["-e", "https://10.20.199.3:8008", "cluster_has_replica"]
     )
@@ -17,9 +19,9 @@ def test_cluster_has_relica_ok(runner: CliRunner, fake_restapi) -> None:
 
 
 def test_cluster_has_replica_ok_with_count_thresholds(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ok")
+    fake_restapi("cluster_has_replica_ok", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -40,9 +42,9 @@ def test_cluster_has_replica_ok_with_count_thresholds(
 
 
 def test_cluster_has_replica_ok_with_sync_count_thresholds(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ok")
+    fake_restapi("cluster_has_replica_ok", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -61,9 +63,9 @@ def test_cluster_has_replica_ok_with_sync_count_thresholds(
 
 
 def test_cluster_has_replica_ok_with_count_thresholds_lag(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ok_lag")
+    fake_restapi("cluster_has_replica_ok_lag", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -86,9 +88,9 @@ def test_cluster_has_replica_ok_with_count_thresholds_lag(
 
 
 def test_cluster_has_replica_ko_with_count_thresholds(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ko")
+    fake_restapi("cluster_has_replica_ko", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -109,9 +111,9 @@ def test_cluster_has_replica_ko_with_count_thresholds(
 
 
 def test_cluster_has_replica_ko_with_sync_count_thresholds(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ko")
+    fake_restapi("cluster_has_replica_ko", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -132,9 +134,9 @@ def test_cluster_has_replica_ko_with_sync_count_thresholds(
 
 
 def test_cluster_has_replica_ko_with_count_thresholds_and_lag(
-    runner: CliRunner, fake_restapi
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_has_replica_ko_lag")
+    fake_restapi("cluster_has_replica_ko_lag", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
diff --git a/tests/test_cluster_node_count.py b/tests/test_cluster_node_count.py
index b6a8b60..0a156c4 100644
--- a/tests/test_cluster_node_count.py
+++ b/tests/test_cluster_node_count.py
@@ -4,14 +4,14 @@ from check_patroni.cli import main
 
 
 def test_cluster_node_count_ok(
-    runner: CliRunner, fake_restapi, use_old_replica_state: bool
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_node_count_ok")
+    fake_restapi("cluster_node_count_ok", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main, ["-e", "https://10.20.199.3:8008", "cluster_node_count"]
     )
     assert result.exit_code == 0
-    if use_old_replica_state:
+    if old_replica_state:
         assert (
             result.output
             == "CLUSTERNODECOUNT OK - members is 3 | healthy_members=3 members=3 role_leader=1 role_replica=2 state_running=3\n"
@@ -24,9 +24,9 @@ def test_cluster_node_count_ok(
 
 
 def test_cluster_node_count_ok_with_thresholds(
-    runner: CliRunner, fake_restapi, use_old_replica_state: bool
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_node_count_ok")
+    fake_restapi("cluster_node_count_ok", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -44,7 +44,7 @@ def test_cluster_node_count_ok_with_thresholds(
         ],
     )
     assert result.exit_code == 0
-    if use_old_replica_state:
+    if old_replica_state:
         assert (
             result.output
             == "CLUSTERNODECOUNT OK - members is 3 | healthy_members=3;@2;@1 members=3;@1;@2 role_leader=1 role_replica=2 state_running=3\n"
@@ -57,9 +57,11 @@ def test_cluster_node_count_ok_with_thresholds(
 
 
 def test_cluster_node_count_healthy_warning(
-    runner: CliRunner, fake_restapi, use_old_replica_state: bool
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_node_count_healthy_warning")
+    fake_restapi(
+        "cluster_node_count_healthy_warning", use_old_replica_state=old_replica_state
+    )
     result = runner.invoke(
         main,
         [
@@ -73,7 +75,7 @@ def test_cluster_node_count_healthy_warning(
         ],
     )
     assert result.exit_code == 1
-    if use_old_replica_state:
+    if old_replica_state:
         assert (
             result.output
             == "CLUSTERNODECOUNT WARNING - healthy_members is 2 (outside range @0:2) | healthy_members=2;@2;@1 members=2 role_leader=1 role_replica=1 state_running=2\n"
@@ -85,8 +87,12 @@ def test_cluster_node_count_healthy_warning(
         )
 
 
-def test_cluster_node_count_healthy_critical(runner: CliRunner, fake_restapi) -> None:
-    fake_restapi("cluster_node_count_healthy_critical")
+def test_cluster_node_count_healthy_critical(
+    runner: CliRunner, fake_restapi, old_replica_state: bool
+) -> None:
+    fake_restapi(
+        "cluster_node_count_healthy_critical", use_old_replica_state=old_replica_state
+    )
     result = runner.invoke(
         main,
         [
@@ -107,9 +113,9 @@ def test_cluster_node_count_healthy_critical(runner: CliRunner, fake_restapi) ->
 
 
 def test_cluster_node_count_warning(
-    runner: CliRunner, fake_restapi, use_old_replica_state: bool
+    runner: CliRunner, fake_restapi, old_replica_state: bool
 ) -> None:
-    fake_restapi("cluster_node_count_warning")
+    fake_restapi("cluster_node_count_warning", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
@@ -123,7 +129,7 @@ def test_cluster_node_count_warning(
         ],
     )
     assert result.exit_code == 1
-    if use_old_replica_state:
+    if old_replica_state:
         assert (
             result.stdout
             == "CLUSTERNODECOUNT WARNING - members is 2 (outside range @0:2) | healthy_members=2 members=2;@2;@1 role_leader=1 role_replica=1 state_running=2\n"
@@ -135,8 +141,10 @@ def test_cluster_node_count_warning(
         )
 
 
-def test_cluster_node_count_critical(runner: CliRunner, fake_restapi) -> None:
-    fake_restapi("cluster_node_count_critical")
+def test_cluster_node_count_critical(
+    runner: CliRunner, fake_restapi, old_replica_state: bool
+) -> None:
+    fake_restapi("cluster_node_count_critical", use_old_replica_state=old_replica_state)
     result = runner.invoke(
         main,
         [
diff --git a/tests/tools.py b/tests/tools.py
index 762a4c7..82f1eb8 100644
--- a/tests/tools.py
+++ b/tests/tools.py
@@ -29,10 +29,10 @@ def my_mock(
         if status != 200:
             raise APIError("Test en erreur pour status code 200")
         if json_file:
-            if use_old_replica_state and (
-                json_file.startswith("cluster_has_replica")
-                or json_file.startswith("cluster_node_count")
-            ):
+            if use_old_replica_state:
+                assert json_file.startswith(
+                    "cluster_has_replica"
+                ) or json_file.startswith("cluster_node_count")
                 return cluster_api_set_replica_running(getjson(json_file))
             return getjson(json_file)
         return None