ninja fix six >=1.12.0
diff --git a/requirements.txt b/requirements.txt
index 9754239..375cada 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -18,6 +18,7 @@
 parse
 pycodestyle
 psutil
+six>=1.12.0
 thrift==0.10.0
 netifaces
 beautifulsoup4