diff --git a/green_framework_test.py b/green_framework_test.py
index 65025798c..037d0279c 100644
--- a/green_framework_test.py
+++ b/green_framework_test.py
@@ -60,8 +60,18 @@ def run(framework_name, *args):
     # Monkey-patch.
     FRAMEWORKS[framework_name]()
 
+    arg_list = list(args)
+
+    # Never run async tests with a framework
+    if len(arg_list) <= 1:
+        arg_list.extend(["-m", "not default_async and default"])
+    else:
+        for i in range(len(arg_list) - 1):
+            if "-m" in arg_list[i]:
+                arg_list[i + 1] = f"not default_async and {arg_list[i + 1]}"
+
     # Run the tests.
-    sys.exit(pytest.main(list(args)))
+    sys.exit(pytest.main(arg_list))
 
 
 def main():
diff --git a/hatch.toml b/hatch.toml
index 25d113e5d..8b1cf93e3 100644
--- a/hatch.toml
+++ b/hatch.toml
@@ -41,7 +41,7 @@ features = ["test"]
 [envs.test.scripts]
 test = "pytest -v --durations=5 --maxfail=10 {args}"
 test-eg = "bash ./.evergreen/run-tests.sh {args}"
-test-async = "test test/asynchronous/ {args}"
+test-async = "pytest -v --durations=5 --maxfail=10 -m default_async {args}"
 test-mockupdb = ["pip install -U git+https://github.com/ajdavis/mongo-mockup-db@master", "test -m mockupdb"]
 
 [envs.encryption]
diff --git a/pyproject.toml b/pyproject.toml
index cfd994f56..4380b57e8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -70,7 +70,7 @@ zstd = ["requirements/zstd.txt"]
 
 [tool.pytest.ini_options]
 minversion = "7"
-addopts = ["-ra", "--strict-config", "--strict-markers", "--junitxml=xunit-results/TEST-results.xml", "-m default"]
+addopts = ["-ra", "--strict-config", "--strict-markers", "--junitxml=xunit-results/TEST-results.xml", "-m default or default_async"]
 testpaths = ["test"]
 log_cli_level = "INFO"
 faulthandler_timeout = 1500
@@ -108,6 +108,7 @@ markers = [
     "load_balancer: load balancer tests",
     "mockupdb: tests that rely on mockupdb",
     "default: default test suite",
+    "default_async: default async test suite",
 ]
 
 [tool.mypy]
diff --git a/test/asynchronous/conftest.py b/test/asynchronous/conftest.py
index 398ba4265..f5bcd953a 100644
--- a/test/asynchronous/conftest.py
+++ b/test/asynchronous/conftest.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from test import pytest_conf
 from test.asynchronous import async_setup, async_teardown
 
 import pytest_asyncio
@@ -14,7 +15,4 @@ async def test_setup_and_teardown():
     await async_teardown()
 
 
-def pytest_collection_modifyitems(items, config):
-    for item in items:
-        if not any(item.iter_markers()):
-            item.add_marker("default")
+pytest_collection_modifyitems = pytest_conf.pytest_collection_modifyitems
diff --git a/test/conftest.py b/test/conftest.py
index 39d29355b..431dd152f 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from test import setup, teardown
+from test import pytest_conf, setup, teardown
 
 import pytest
 
@@ -14,7 +14,4 @@ def test_setup_and_teardown():
     teardown()
 
 
-def pytest_collection_modifyitems(items, config):
-    for item in items:
-        if not any(item.iter_markers()):
-            item.add_marker("default")
+pytest_collection_modifyitems = pytest_conf.pytest_collection_modifyitems
diff --git a/test/pytest_conf.py b/test/pytest_conf.py
new file mode 100644
index 000000000..75f3e7432
--- /dev/null
+++ b/test/pytest_conf.py
@@ -0,0 +1,16 @@
+from __future__ import annotations
+
+
+def pytest_collection_modifyitems(items, config):
+    sync_items = []
+    async_items = [
+        item
+        for item in items
+        if "asynchronous" in item.fspath.dirname or sync_items.append(item)  # type: ignore[func-returns-value]
+    ]
+    for item in async_items:
+        if not any(item.iter_markers()):
+            item.add_marker("default_async")
+    for item in sync_items:
+        if not any(item.iter_markers()):
+            item.add_marker("default")
diff --git a/tools/synchro.py b/tools/synchro.py
index e0af50229..5711e1f84 100644
--- a/tools/synchro.py
+++ b/tools/synchro.py
@@ -95,6 +95,7 @@ replacements = {
     "aclose": "close",
     "async-transactions-ref": "transactions-ref",
     "async-snapshot-reads-ref": "snapshot-reads-ref",
+    "default_async": "default",
 }
 
 docstring_replacements: dict[tuple[str, str], str] = {