diff --git a/tox.ini b/tox.ini
index e274fc8d2..07552ba8d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -57,6 +57,7 @@ deps =
     # Twisted[http2] is required to import some files
     Twisted[http2]>=17.9.0
     pytest-flake8
+    flake8==3.9.2  # https://github.com/tholo/pytest-flake8/issues/81
 commands =
     py.test --flake8 {posargs:docs scrapy tests}