diff --git a/requirements_dev.txt b/requirements_dev.txt
index fb209cf..4cfbe6b 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,7 +1,7 @@
 pip>=20.2.2
 wheel>=0.34.2
 watchdog==2.0.2
-flake8==3.8.4
+flake8==3.9.0
 tox==3.23.0
 coverage==5.5
 Sphinx==3.5.2