diff --git a/cylc/uiserver/tests/test_auth.py b/cylc/uiserver/tests/test_auth.py
index 5cb9e3ea..07452f63 100644
--- a/cylc/uiserver/tests/test_auth.py
+++ b/cylc/uiserver/tests/test_auth.py
@@ -21,6 +21,7 @@
 from tornado.httpclient import HTTPClientError
 
 
+@pytest.mark.asyncio
 @pytest.mark.integration
 @pytest.mark.usefixtures("mock_authentication")
 async def test_cylc_handler(patch_conf_files, jp_fetch):
@@ -31,6 +32,7 @@ async def test_cylc_handler(patch_conf_files, jp_fetch):
     assert resp.code == 200
 
 
+@pytest.mark.asyncio
 @pytest.mark.integration
 @pytest.mark.usefixtures("mock_authentication")
 @pytest.mark.parametrize(
@@ -70,6 +72,7 @@ async def test_authorised_and_authenticated(
     await _test(jp_fetch, endpoint, code, message, body)
 
 
+@pytest.mark.asyncio
 @pytest.mark.integration
 @pytest.mark.usefixtures("mock_authentication_none")
 @pytest.mark.parametrize(
@@ -109,6 +112,7 @@ async def test_unauthenticated(
     await _test(jp_fetch, endpoint, code, message, body)
 
 
+@pytest.mark.asyncio
 @pytest.mark.integration
 @pytest.mark.usefixtures("mock_authentication_yossarian")
 @pytest.mark.parametrize(
diff --git a/cylc/uiserver/tests/test_graphql.py b/cylc/uiserver/tests/test_graphql.py
index d0b26d0b..0681151c 100644
--- a/cylc/uiserver/tests/test_graphql.py
+++ b/cylc/uiserver/tests/test_graphql.py
@@ -57,6 +57,7 @@ async def _fetch(*endpoint, query=None, headers=None):
     return _fetch
 
 
+@pytest.mark.asyncio
 async def test_query(gql_query, dummy_workflow):
     """Test sending the most basic GraphQL query."""
     # configure two dummy workflows so we have something to look at
@@ -93,6 +94,7 @@ async def test_query(gql_query, dummy_workflow):
     }
 
 
+@pytest.mark.asyncio
 async def test_multi(gql_query, monkeypatch, cylc_uis, dummy_workflow):
     """Ensure multi-mutation requests are properly forwarded.
 
diff --git a/cylc/uiserver/tests/test_workflows_mgr.py b/cylc/uiserver/tests/test_workflows_mgr.py
index c6cbd3f0..57928861 100644
--- a/cylc/uiserver/tests/test_workflows_mgr.py
+++ b/cylc/uiserver/tests/test_workflows_mgr.py
@@ -281,6 +281,7 @@ async def test_multi_request_gather_errors(
     assert caplog.records[0].exc_info[0] == error_type
 
 
+@pytest.mark.asyncio
 async def test_crashed_workflow(one_workflow_aiter, caplog, uis_caplog):
     """It should swallow client connect errors."""
     # create a UIS, configure it for logging