diff --git a/requirements.txt b/requirements.txt
index d028f82..0511c69 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -23,7 +23,7 @@ python-mimeparse==1.6.0
 pytz==2018.7
 requests==2.20.0
 rsa==4.0
-six==1.11.0
+six==1.15.0
 typed-ast==1.1.0
 urllib3==1.24.2
 wrapt==1.10.11