diff --git a/requirements.txt b/requirements.txt
index ba23c2721..ddfae6b33 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@ pyexcel-io==0.5.7
 pyexcel-xls==0.5.7
 pyexcel-xlsx==0.5.6
 pyexcel-ods3==0.5.2
-pytz==2018.4
+pytz==2018.5
 gunicorn==19.8.1
 whitenoise==3.3.1  #manages static assets
 eventlet==0.22.1