diff --git a/tests/_async/test_http2.py b/tests/_async/test_http2.py
index 2c415e42..bd27df56 100644
--- a/tests/_async/test_http2.py
+++ b/tests/_async/test_http2.py
@@ -52,6 +52,7 @@ async def test_http2_connection():
         )
 
 
+@pytest.mark.anyio
 async def test_http2_connection_closed():
     origin = Origin(b"https", b"example.com", 443)
     stream = AsyncMockStream(
diff --git a/tests/_sync/test_http2.py b/tests/_sync/test_http2.py
index 1cf90feb..df4cfcbc 100644
--- a/tests/_sync/test_http2.py
+++ b/tests/_sync/test_http2.py
@@ -52,6 +52,7 @@ def test_http2_connection():
         )
 
 
+
 def test_http2_connection_closed():
     origin = Origin(b"https", b"example.com", 443)
     stream = MockStream(