diff --git a/README.md b/README.md
index c47d7b38..73012297 100644
--- a/README.md
+++ b/README.md
@@ -208,10 +208,13 @@ We use [pytest](http://doc.pytest.org/en/latest/) for **running tests**:
 pytest jupyterhub/tests
 ```
 
-If you see test failures because of timeouts, you may wish to increase the timeout from the default of 5 seconds:
+If you see test failures because of timeouts, you may wish to increase the
+`ASYNC_TEST_TIMEOUT` used by the
+[pytest-tornado-plugin](https://github.com/eugeniy/pytest-tornado/blob/c79f68de2222eb7cf84edcfe28650ebf309a4d0c/README.rst#markers)
+from the default of 5 seconds:
 
 ```bash
-export ASYNC_TEST_TIMEOUT=30
+export ASYNC_TEST_TIMEOUT=15
 ```
 
 ### Building the Docs locally