diff --git a/requirements.txt b/requirements.txt
index 876338e3c..2e699800c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ matplotlib==2.0.2
 tox==2.7.0
 
 # code style
-flake8==3.3.0
+flake8==3.4.1
 pydocstyle==2.0.0
 mypy==0.520