diff --git a/requirements.txt b/requirements.txt
index f76faae..f759109 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,6 +3,5 @@ jinja2==2.10
 jsonschema==3.0.1
 openpyxl==2.5.4
 netaddr==0.7.19
-pyyaml==3.12
+pyyaml==5.1
 requests==2.21.0
-six==1.12.0