diff --git a/conftest.py b/conftest.py
index 106f4c9e0..f33ffb1a4 100644
--- a/conftest.py
+++ b/conftest.py
@@ -48,6 +48,14 @@ def chdir(tmpdir):
     tmpdir.chdir()
 
 
+def pytest_addoption(parser):
+    parser.addoption(
+        "--reactor",
+        default="default",
+        choices=["default", "asyncio"],
+    )
+
+
 @pytest.fixture(scope="class")
 def reactor_pytest(request):
     if not request.cls:
@@ -58,11 +66,8 @@ def reactor_pytest(request):
 
 
 @pytest.fixture(autouse=True)
-def only_asyncio(request):
-    if (
-        request.node.get_closest_marker("only_asyncio")
-        and request.config.getoption("--reactor") != "asyncio"
-    ):
+def only_asyncio(request, reactor_pytest):
+    if request.node.get_closest_marker("only_asyncio") and reactor_pytest != "asyncio":
         pytest.skip("This test is only run with --reactor=asyncio")
 
 
diff --git a/tests/test_spider_yield_seeds.py b/tests/test_spider_yield_seeds.py
index dcda67f29..a65a0fb51 100644
--- a/tests/test_spider_yield_seeds.py
+++ b/tests/test_spider_yield_seeds.py
@@ -1,51 +1,41 @@
 from asyncio import sleep
 
 import pytest
-from pytest_twisted import ensureDeferred
+from twisted.internet.defer import inlineCallbacks
+from twisted.trial.unittest import TestCase
 
 from scrapy import Spider, signals
 from scrapy.core.engine import ExecutionEngine
 from scrapy.utils.test import get_crawler
 
 
-class Scenario:
-    pass
+class MainTestCase(TestCase):
+    @inlineCallbacks
+    def _test_scenario(self, scenario):
+        class TestSpider(Spider):
+            name = "test"
+            yield_seeds = scenario.yield_seeds
 
+        actual_items = []
 
-class AsyncioScenario(Scenario):
-    expected_items = [{"a": "b"}]
-    only_asyncio = True
+        def track_item(item, response, spider):
+            actual_items.append(item)
 
-    async def yield_seeds(self):
-        await sleep(ExecutionEngine._SLOT_HEARTBEAT_INTERVAL + 0.01)
-        yield {"a": "b"}
+        crawler = get_crawler(TestSpider)
+        crawler.signals.connect(track_item, signals.item_scraped)
+        yield crawler.crawl()
+        assert crawler.stats.get_value("finish_reason") == "finished"
+        assert actual_items == scenario.expected_items
 
+    @pytest.mark.only_asyncio
+    @inlineCallbacks
+    def test_asyncio_delayed(self):
+        class Scenario:
+            expected_items = [{"a": "b"}]
+            only_asyncio = True
 
-@pytest.mark.parametrize(
-    "scenario",
-    [
-        pytest.param(
-            scenario,
-            marks=pytest.mark.only_asyncio
-            if getattr(scenario, "only_asyncio", False)
-            else [],
-        )
-        for scenario in Scenario.__subclasses__()
-    ],
-)
-@ensureDeferred
-async def test_main(scenario):
-    class TestSpider(Spider):
-        name = "test"
-        yield_seeds = scenario.yield_seeds
+            async def yield_seeds(self):
+                await sleep(ExecutionEngine._SLOT_HEARTBEAT_INTERVAL + 0.01)
+                yield {"a": "b"}
 
-    actual_items = []
-
-    def track_item(item, response, spider):
-        actual_items.append(item)
-
-    crawler = get_crawler(TestSpider)
-    crawler.signals.connect(track_item, signals.item_scraped)
-    await crawler.crawl()
-    assert crawler.stats.get_value("finish_reason") == "finished"
-    assert actual_items == scenario.expected_items
+        yield self._test_scenario(Scenario)
diff --git a/tox.ini b/tox.ini
index 71a58d52f..041fcffca 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,6 @@ deps =
     pygments
     pytest != 8.2.*  # https://github.com/pytest-dev/pytest/issues/12275
     pytest-cov >= 4.0.0
-    pytest-twisted
     pytest-xdist
     sybil >= 1.3.0  # https://github.com/cjw296/sybil/issues/20#issuecomment-605433422
     testfixtures