diff --git a/requirements.dev.txt b/requirements.dev.txt
index 15d6f54..ca13b06 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -1,4 +1,4 @@
-flake8==3.8.3
+flake8==3.9.0
 invoke==1.4.1
 mkdocs==1.1.2
 pre-commit==2.7.1