diff --git a/requirements-dev.txt b/requirements-dev.txt
index 61f007c..21fb73d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -7,7 +7,7 @@ pyflakes==2.0.0
 py==1.5.3
 atomicwrites==1.0
 more-itertools==4.0.0
-six==1.10.0
+six==1.17.0
 attrs==17.4.0
 pluggy==0.6.0
 pytest==3.6.1