diff --git a/tests/requirements-py3.txt b/tests/requirements-py3.txt
index 05b794d81..91fa1c5b5 100644
--- a/tests/requirements-py3.txt
+++ b/tests/requirements-py3.txt
@@ -2,6 +2,7 @@
 jmespath
 mitmproxy; python_version >= '3.6'
 mitmproxy<4.0.0; python_version < '3.6'
+# https://github.com/pytest-dev/pytest-twisted/issues/93
 pytest != 5.4, != 5.4.1
 pytest-cov
 pytest-twisted >= 1.11