diff --git a/requirements-dev.txt b/requirements-dev.txt
index 1f663e1..bdeb499 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,4 +1,4 @@
 -r requirements.txt
-flake8==3.7.7
+flake8==3.9.0
 twine==1.13.0
 wheel==0.33.1