diff --git a/requirements_dev.txt b/requirements_dev.txt
index c7984aa..3f9fd4f 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -17,7 +17,7 @@ watchdog==0.8.3
 pytest==3.2.1
 pytest-runner==2.11.1
 tox==2.7.0
-flake8==3.4.1
+flake8==3.9.2
 coverage==4.4.1
 Sphinx==1.6.3
 sphinxcontrib-napoleon==0.6.1