diff --git a/log_request_id/tests.py b/log_request_id/tests.py
index 9440c2a..ec88320 100644
--- a/log_request_id/tests.py
+++ b/log_request_id/tests.py
@@ -163,6 +163,7 @@ def inner():
         self.assertRaises(ImproperlyConfigured, inner)
 
 
+# asgiref is required from Django 3.0
 if async_to_sync:
 
     class AsyncRequestIDLoggingTestCase(RequestIDLoggingTestCase):