diff --git a/requirements_dev.txt b/requirements_dev.txt
index f7e99b2..8048763 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -2,7 +2,7 @@ pip==21.0.1
 bumpversion==0.6.0
 wheel==0.36.2
 watchdog==2.0.2
-flake8==3.8.4
+flake8==3.9.0
 tox==3.23.0
 coverage==5.5
 Sphinx==3.4.3